Ultimate Guide: Environmental Systems and Societies (HL)

Chapter 1

Environmental Systems and Societies: Foundation

Environmental Systems and Societies (ESS) is an interdisciplinary subject that explores the relationships between humans and the environment, integrating both science and socioeconomic perspectives. The foundational aspects of ESS provide students with the essential understanding of how environmental systems function, how human activities affect these systems, and how societies can work toward sustainable solutions.

The foundation of ESS is built upon several key concepts that shape how we understand environmental issues. These include systems theory, sustainability, ecology, and the interactions between humans and the environment. Let’s explore each of these in more detail.

1. Systems Theory

A core principle of ESS is the idea of systems. In environmental science, a system refers to a set of interrelated components that work together within a defined boundary. Environmental systems can be open or closed and may range from small ecosystems to the entire Earth system.

Key Concepts of Systems Theory:

• Inputs: These are the resources or energy entering a system. For example, sunlight entering an ecosystem.

• Throughputs: These are processes that occur within a system. In an ecosystem, this might be the process of photosynthesis or nutrient cycling.

• Outputs: These are the results of system processes, such as heat, energy, or waste products that leave the system.

Systems in environmental science are typically divided into two categories:

• Open Systems: These systems exchange both matter and energy with their surroundings (e.g., ecosystems).

• Closed Systems: These systems exchange only energy with their surroundings and not matter (e.g., Earth itself).

The study of feedback loops is also crucial in systems theory:

• Positive Feedback: Amplifies changes and leads to instability (e.g., the melting of polar ice caps reducing the Earth’s reflectivity, causing more heat absorption and further melting).

• Negative Feedback: Stabilizes the system and maintains equilibrium (e.g., the regulation of body temperature in humans).

2. Sustainability

At the heart of ESS is the concept of sustainability—the idea that human societies must meet their needs without compromising the ability of future generations to meet their own needs. Sustainability is crucial for understanding how we should use resources in ways that don't degrade ecosystems and contribute to long-term environmental harm.

Three Pillars of Sustainability:

• Environmental Sustainability: Maintaining healthy ecosystems and biodiversity, preventing overexploitation of natural resources, and managing waste and pollution.

• Economic Sustainability: Creating economic systems that provide prosperity while not depleting natural resources. This often includes green technologies, sustainable businesses, and fair trade.

• Social Sustainability: Ensuring that human societies are equitable, provide access to resources, and maintain a healthy standard of living for all people.

Sustainability encourages balance between economic growth, environmental protection, and social equity.

3. Ecology and Energy Flow

Ecology is the study of the relationships between living organisms and their environment. ESS focuses on how ecosystems function and how energy and matter flow through them. The fundamental processes include:

• Energy Flow: Energy flows through ecosystems in one direction, starting with sunlight and moving through the food chain via producers (plants) to consumers (herbivores, carnivores) and decomposers (bacteria, fungi).

  • Trophic Levels: Organisms in ecosystems are grouped based on their position in the food chain (producers, primary consumers, secondary consumers, etc.). As energy moves through each level, much is lost as heat due to the second law of thermodynamics, which is why food chains typically only consist of 4-5 trophic levels.

• Nutrient Cycles: The recycling of nutrients within ecosystems, such as the carbon cycle, nitrogen cycle, and water cycle. These cycles allow for the constant reuse of essential nutrients needed by organisms to survive.

• Ecological Pyramids: These are visual representations of energy flow, biomass, or numbers at each trophic level in an ecosystem. They illustrate that energy is lost as it moves through the system, making higher trophic levels less energy-efficient.

4. Human Impacts on the Environment

Environmental Systems and Societies also emphasizes understanding how human activities affect the environment. Humans have both direct and indirect effects on ecosystems and the climate. These impacts are a major focus of ESS as students learn how to address environmental challenges.

Key Human Impacts:

• Deforestation: The large-scale removal of forests for agriculture, logging, and urban development, which leads to habitat loss, reduced biodiversity, and carbon emissions.

• Pollution: Human activities produce different types of pollution (air, water, soil, and noise) that harm ecosystems and human health. For example, the burning of fossil fuels creates air pollution, while the release of chemicals can contaminate water supplies.

• Climate Change: Human-caused climate change, primarily driven by the burning of fossil fuels and deforestation, results in an increase in greenhouse gases, leading to global warming, sea level rise, and extreme weather events.

• Overfishing: Unsustainable fishing practices deplete fish stocks, disrupt marine ecosystems, and affect global food security.

• Urbanization: The growth of cities often leads to habitat destruction, increased pollution, and higher resource consumption.

5. Environmental Ethics

Another key aspect of ESS is the study of environmental ethics, which looks at how societies value the environment and make decisions about natural resource use. There are different schools of thought when it comes to ethics and the environment, including:

• Anthropocentrism: The belief that human needs and desires should take priority over the environment.

• Biocentrism: The belief that all living organisms have inherent value, regardless of their utility to humans.

• Ecocentrism: The belief that ecosystems as a whole, including non-living components, have intrinsic value and should be preserved.

These ethical perspectives guide how environmental policies and decisions are made at the local, national, and global levels.

6. Environmental Challenges and Solutions

ESS provides an understanding of various environmental challenges that arise due to human interaction with natural systems. Key global environmental challenges include:

• Biodiversity loss: The decline of species and ecosystems worldwide due to habitat destruction, climate change, and pollution.

• Resource depletion: Overconsumption of resources like water, fossil fuels, and minerals, leading to scarcity.

• Waste management: Improper disposal of waste and the accumulation of pollutants in landfills and oceans.

• Food security: Ensuring access to sufficient, nutritious food for a growing global population while minimizing environmental impact.

Sustainable Solutions:

ESS encourages students to explore sustainable solutions for these challenges, such as:

• Renewable energy: Wind, solar, and hydroelectric power as alternatives to fossil fuels.

• Conservation: Protecting natural habitats and wildlife through conservation efforts like protected areas and sustainable land use practices.

• Sustainable agriculture: Techniques like organic farming, crop rotation, and permaculture to reduce environmental degradation while ensuring food security.

• Circular economy: Reducing waste by reusing materials, recycling, and minimizing consumption.

1.1. Systems Theory in Environmental Science

Systems theory is foundational to understanding how environmental processes work and interact. In ESS, systems theory helps us examine how various environmental components—such as ecosystems, climate systems, and human societies—operate as interconnected units.

A. Components of a System

A system is a set of interacting components that form a unified whole. It is typically divided into inputs, throughputs, and outputs.

• Inputs: These are the energy or materials that enter a system. For example, in an ecosystem, the primary input is solar energy, which drives photosynthesis.

• Throughputs: These are the processes that take place within the system. In the case of an ecosystem, photosynthesis, nutrient cycling, and energy transfer through food chains are examples of throughputs.

• Outputs: These are the results or products of a system's processes. Outputs can be energy, matter, or waste. In an ecosystem, outputs could include organic matter released as detritus or excess heat energy radiated into the atmosphere.

B. Types of Systems

• Open Systems: These systems exchange both energy and matter with their surroundings. For example, a forest ecosystem is an open system because it exchanges energy (sunlight) and matter (water, carbon dioxide, nutrients) with the environment.

• Closed Systems: These systems exchange energy but not matter with their surroundings. Earth, as a whole, is often considered a closed system because it exchanges solar energy with space but does not exchange large amounts of matter (other than minor transfers like meteorites).

C. Feedback Mechanisms

• Positive Feedback: This occurs when a change in a system triggers processes that amplify that change, often leading to a reinforcing cycle. A classic example is the melting of ice caps—as ice melts due to warming, the Earth’s surface absorbs more heat (because ice reflects sunlight), causing even more ice to melt.

• Negative Feedback: In contrast, negative feedback reduces the effect of a change in a system, helping to restore balance. An example is body temperature regulation in humans. If the body gets too hot, sweating occurs to cool it down, while if it gets too cold, the body shivers to generate warmth, returning the body to equilibrium.

2.1. Sustainability

Sustainability is a central principle of ESS. It focuses on ensuring that human development does not undermine the ability of future generations to meet their own needs.

A. Three Pillars of Sustainability

Sustainability is commonly broken down into three interconnected pillars: environmental, economic, and social sustainability.

• Environmental Sustainability: This involves protecting natural systems and resources in ways that maintain their health and resilience. It includes:

  • Conservation of biodiversity: Protecting species and ecosystems from extinction and degradation.

  • Resource management: Ensuring that resources like water, energy, and raw materials are used efficiently and replenished.

  • Pollution control: Minimizing the release of pollutants into air, water, and soil.

• Economic Sustainability: This focuses on creating economic systems that support long-term prosperity without degrading the environment. Key aspects include:

  • Green technologies: Innovations that reduce the environmental impact of production, transportation, and energy generation.

  • Circular economy: Reducing waste by reusing materials, recycling, and designing products that have longer lifespans or are easily recyclable.

  • Fair trade: Promoting equitable economic practices that ensure workers in developing countries receive fair wages and good working conditions.

• Social Sustainability: Ensuring social equity and well-being for all members of society, both in the present and the future. This involves:

  • Access to education, healthcare, and resources: Reducing inequality so that people can thrive regardless of their background.

  • Community development: Supporting local communities in becoming self-sufficient, resilient, and empowered to meet their needs.

  • Social justice: Ensuring that environmental benefits and burdens are shared equitably among all groups, including marginalized communities.

B. Sustainable Development Goals (SDGs)

The United Nations established the 17 Sustainable Development Goals (SDGs) in 2015 to address global challenges related to poverty, inequality, environmental degradation, and peace. These goals emphasize a holistic approach to sustainability, integrating social, economic, and environmental concerns.

3.1. Ecology and Energy Flow

Ecology is the study of how organisms interact with each other and with their physical environment. It is integral to understanding how ecosystems function and how energy flows through them.

A. Energy Flow in Ecosystems

Energy flows through ecosystems in a one-way direction. The primary source of energy for almost all ecosystems is sunlight, which is captured by producers (primarily plants) through photosynthesis.

• Producers (Autotrophs): Organisms that can produce their own food using sunlight, such as plants, algae, and some bacteria.

• Consumers (Heterotrophs): Organisms that must consume other organisms for energy. Consumers include:

  • Primary consumers: Herbivores that eat producers.

  • Secondary consumers: Carnivores that eat herbivores.

  • Tertiary consumers: Top predators in the food chain.

• Decomposers: Organisms such as fungi and bacteria that break down dead organic matter and return nutrients to the soil.

As energy moves up the food chain, much of it is lost as heat due to the second law of thermodynamics, which states that energy is not perfectly transferred in a system. Therefore, food chains are typically short, often with only 4–5 trophic levels.

B. Nutrient Cycles

Nutrient cycling is the process by which elements like carbon, nitrogen, and phosphorus are recycled in the ecosystem. These cycles ensure that essential nutrients are available for organisms to use.

• Carbon Cycle: The process by which carbon is exchanged between the atmosphere, oceans, soil, and living organisms. This cycle is key to regulating Earth's climate, as carbon dioxide is a significant greenhouse gas.

• Nitrogen Cycle: Nitrogen is a critical component of amino acids and proteins. It moves through the atmosphere, soil, and living organisms in a series of biological processes, including nitrogen fixation, nitrification, and denitrification.

• Phosphorus Cycle: Phosphorus, an essential nutrient for plant growth, is cycled through the environment primarily in the form of phosphate. Unlike carbon and nitrogen, phosphorus does not have a gaseous phase and instead moves through soil and water.

4.1. Human Impacts on the Environment

Human activities have significant impacts on the environment, many of which are unsustainable and contribute to environmental degradation.

A. Deforestation

Deforestation occurs when forests are cleared for agriculture, logging, or urban development. This process disrupts ecosystems, leading to habitat loss, reduced biodiversity, and an increase in carbon emissions due to the burning or decomposition of trees.

B. Pollution

Human activities release various pollutants into the environment. These pollutants can be classified as:

• Air pollution: Emissions from vehicles, factories, and agriculture contribute to the release of harmful gases like carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen oxides (NOx).

• Water pollution: Chemicals, plastic waste, and untreated sewage contaminate freshwater and marine environments.

• Soil pollution: Pesticides, industrial waste, and urban development degrade soil quality, reducing its fertility and affecting food production.

• Noise pollution: Urbanization, transportation, and industrial activities generate high levels of noise that disrupt wildlife and human health.

C. Climate Change

The burning of fossil fuels for energy, transportation, and industrial processes has increased concentrations of greenhouse gases, such as CO2, in the atmosphere. This leads to global warming, which causes rising sea levels, more extreme weather events, and disruptions to ecosystems and agriculture.

D. Overfishing

Overfishing occurs when fish are caught at rates faster than they can reproduce, leading to population declines and the collapse of marine ecosystems. Overfishing also disrupts food chains and threatens food security for humans.

E. Urbanization

The expansion of cities has led to habitat destruction, increased pollution, and greater demand for resources. Urban sprawl contributes to the loss of biodiversity and the degradation of local ecosystems.

5.1. Environmental Ethics

Environmental ethics explores how humans should interact with the natural world. Different ethical frameworks help guide decisions about how to use and conserve natural resources.

A. Anthropocentrism

This human-centered view prioritizes human needs and interests above those of other species and the environment. According to this view, nature exists primarily for human use and benefit.

B. Biocentrism

Biocentrism argues that all living organisms have inherent value, regardless of their utility to humans. This ethical perspective advocates for the protection of ecosystems and biodiversity, emphasizing the importance of all life forms.

C. Ecocentrism

Ecocentrism takes a holistic approach, valuing entire ecosystems—including non-living components like air, water, and soil. From this perspective, ecosystems should be preserved as a whole, and human activity should respect the balance and integrity of natural systems.

Chapter 2

Ecology

Introduction to Ecological Systems

1. What is Ecology?

• Definition: Ecology is the branch of biology that deals with the study of interactions among organisms and their environment. It explores how organisms interact with each other and with their physical surroundings, including both living (biotic) and non-living (abiotic) components.

• Key Concepts:

  • Interdependence: The idea that organisms and their environments are interconnected, and changes in one part of the ecosystem can affect other parts.

  • Holistic Approach: Ecology often requires studying systems as a whole rather than in isolated parts, recognizing that biological, chemical, and physical processes are interconnected.

• Levels of Ecological Organization:

  • Individual: Focuses on how individual organisms survive, reproduce, and adapt to their environment.

  • Population: A group of individuals of the same species living in a particular geographic area. Population ecology studies factors that affect population size and composition.

  • Community: Consists of all the populations of different species living and interacting in an area. Community ecology examines interactions among species, such as competition, predation, and symbiosis.

  • Ecosystem: An ecosystem includes both the community of living organisms and the non-living components of the environment (such as air, water, and minerals) with which they interact. Ecosystem ecology studies energy flow and nutrient cycling within ecosystems.

  • Biosphere: The biosphere is the global sum of all ecosystems and represents the zone of life on Earth. It includes the atmosphere, hydrosphere, and lithosphere where living organisms exist.

2. Components of an Ecosystem

a. Biotic Factors (Living Components)

Biotic factors are the living components of an ecosystem that directly or indirectly affect other organisms. These factors include all organisms, from the smallest microorganisms to the largest animals, and the interactions between them.

• Categories of Biotic Factors:

  • Producers (Autotrophs):

Definition: Organisms that produce their own food using sunlight (photosynthesis) or chemical energy (chemosynthesis).

Examples:

• Plants: Trees, grasses, and shrubs that convert sunlight into energy through photosynthesis.

• Algae: Aquatic producers that form the basis of many marine and freshwater food chains.

• Cyanobacteria: Photosynthetic bacteria that also contribute to energy production in aquatic ecosystems.

Role in Ecosystem: Producers are the primary source of energy for other organisms in an ecosystem. They form the base of the food chain and support all other trophic levels.

• Consumers (Heterotrophs):

Definition: Organisms that cannot produce their own food and must consume other organisms to obtain energy.

Types of Consumers:

• Primary Consumers (Herbivores):

  • Definition: Organisms that feed directly on producers.

  • Examples: Cows, deer, rabbits, and caterpillars.

  • Role in Ecosystem: Primary consumers transfer energy from producers to higher trophic levels and help in seed dispersal.

• Secondary Consumers (Carnivores):

  • Definition: Organisms that feed on primary consumers.

  • Examples: Frogs, snakes, and foxes.

  • Role in Ecosystem: Secondary consumers control herbivore populations and maintain balance in the ecosystem.

• Tertiary Consumers (Top Predators):

  • Definition: Organisms at the top of the food chain that feed on secondary consumers.

  • Examples: Lions, eagles, and sharks.

  • Role in Ecosystem: Tertiary consumers regulate populations of secondary consumers and contribute to ecosystem stability.

• Omnivores:

  • Definition: Organisms that consume both plants and animals.

  • Examples: Humans, bears, and raccoons.

  • Role in Ecosystem: Omnivores occupy multiple trophic levels and help in both plant and animal population control.

• Decomposers (Saprotrophs):

Definition: Organisms that break down dead organic matter and waste, recycling nutrients back into the ecosystem.

Examples:

• Fungi: Mushrooms, molds, and yeasts that decompose dead organic material.

• Bacteria: Microscopic organisms that play a critical role in nutrient cycling by breaking down complex organic compounds.

• Detritivores: Organisms like earthworms and vultures that consume detritus (dead organic material).

Role in Ecosystem: Decomposers are essential for nutrient recycling, breaking down dead organisms and waste into simpler substances that can be reused by producers.

• Interactions Among Biotic Factors:

  • Competition: Occurs when organisms vie for the same resources (e.g., food, water, space) within an ecosystem. This can be within the same species (intraspecific) or between different species (interspecific).

  • Predation: The interaction where one organism (predator) hunts and consumes another organism (prey). This relationship influences population dynamics and evolutionary adaptations.

  • Symbiosis: A close, long-term interaction between different species. Symbiotic relationships can be mutualistic (both benefit), commensal (one benefits, the other is unaffected), or parasitic (one benefits at the expense of the other).

  • Herbivory: A specific type of predation where herbivores consume plants. This interaction can influence plant community composition and structure.

b. Abiotic Factors (Non-living Components)

Abiotic factors are the non-living physical and chemical components of an ecosystem that affect living organisms and the functioning of the ecosystem. These factors help shape the environment and influence the distribution and behavior of organisms.

• Major Abiotic Factors:

  • Climate:

    • Definition: The long-term patterns of temperature, humidity, wind, and precipitation in a region.

    • Components of Climate:

      • Temperature: Influences metabolic rates and the geographical distribution of species.

      • Precipitation: Availability of water, essential for all living organisms.

      • Wind: Affects temperature regulation, seed dispersal, and evaporation rates.

    • Impact on Ecosystem: Climate determines the types of organisms that can survive in a particular region and influences the types of ecosystems (biomes) that develop, such as deserts, forests, or tundras.

  • Soil:

    • Definition: The upper layer of the Earth's surface where plants grow, consisting of organic matter, minerals, gases, liquids, and organisms.

    • Components of Soil:

      • Mineral Content: Provides essential nutrients like nitrogen, phosphorus, and potassium.

      • pH Level: Influences nutrient availability and microbial activity.

      • Texture: Affects water retention and root penetration.

    • Impact on Ecosystem: Soil quality influences plant growth, which in turn supports herbivores and higher trophic levels. Different soil types can support different plant communities.

  • Water:

    • Definition: A vital component of life, required for biochemical processes, nutrient transport, and temperature regulation.

    • Availability: Varies by region, affecting ecosystem productivity and species distribution.

    • Quality: Includes factors like salinity, pH, and dissolved oxygen levels, which influence the types of organisms that can thrive in an aquatic environment.

    • Impact on Ecosystem: Water availability determines the types of ecosystems present (e.g., freshwater, marine, wetland) and supports life processes such as hydration, nutrient uptake, and waste removal.

  • Sunlight:

    • Definition: The main energy source for life on Earth, driving photosynthesis in producers.

    • Intensity: Affects the rate of photosynthesis and the productivity of an ecosystem.

    • Duration: The length of daylight influences biological rhythms, plant flowering, and animal behavior.

    • Impact on Ecosystem: Sunlight influences the distribution of organisms, especially plants, and affects the structure of ecosystems. In aquatic ecosystems, light penetration determines the depth at which photosynthesis can occur.

  • Nutrients:

    • Definition: Essential chemical elements required by organisms for growth, reproduction, and survival.

    • Key Nutrients: Include carbon, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

    • Nutrient Cycling: Nutrients cycle through ecosystems via biogeochemical cycles (e.g., carbon cycle, nitrogen cycle), and their availability can limit the productivity of an ecosystem.

    • Impact on Ecosystem: Nutrient availability influences plant growth and the overall productivity of an ecosystem. Nutrient imbalances can lead to problems like eutrophication in aquatic systems.

  • Topography:

    • Definition: The physical features of the Earth's surface, including elevation, slope, and orientation.

    • Impact on Ecosystem:

Elevation: Affects temperature and oxygen levels, influencing the types of organisms that can survive at different altitudes.

Slope: Influences water runoff and soil erosion, affecting vegetation patterns.

Orientation: Determines the amount of sunlight received, affecting microclimates within an ecosystem.

• Interactions Between Abiotic and Biotic Factors:

  • Adaptations: Organisms evolve adaptations that allow them to survive and reproduce in response to abiotic factors. For example, desert plants have adaptations like thick leaves and deep roots to conserve water.

  • Habitat Suitability: The combination of abiotic factors in an environment determines the suitability of a habitat for different species.

  • Ecosystem Dynamics: Abiotic factors influence the productivity, diversity, and stability of ecosystems. Changes in abiotic factors, such as climate change or pollution, can lead to shifts in ecosystem structure and function.

These biotic and abiotic factors interact to shape the structure and dynamics of ecosystems, influencing everything from individual survival to the functioning of entire biomes. 

3. Energy Flow in Ecosystems

• The Concept of Energy Flow:

  • Solar Energy as the Primary Source: The vast majority of ecosystems on Earth derive their energy from the sun. Solar energy is captured by producers (through photosynthesis) and converted into chemical energy in the form of glucose, which is then used by other organisms.

  • Photosynthesis: A process in which producers convert light energy into chemical energy stored in glucose (C6H12O6). The basic equation for photosynthesis is: 

• Food Chains and Food Webs:

  • Food Chain: A linear sequence of organisms where each is consumed by the next member in the chain. It illustrates a direct pathway of energy flow in an ecosystem.

  • Food Web: A more complex and realistic representation of energy flow in an ecosystem. It shows multiple interconnected food chains and the various paths through which energy and nutrients travel within an ecosystem.

• Trophic Levels:

  • Primary Producers: The first trophic level, consisting of organisms that produce their own food.

  • Primary Consumers: Herbivores that feed directly on producers, representing the second trophic level.

  • Secondary Consumers: Carnivores that feed on primary consumers, representing the third trophic level.

  • Tertiary Consumers: Higher-level carnivores that feed on secondary consumers.

  • Quaternary Consumers: Apex predators at the top of the food chain with no natural predators.

  • Decomposers: Although not typically represented in a specific trophic level, decomposers break down dead organic material from all levels, returning nutrients to the ecosystem.

• Energy Transfer Efficiency:

  • 10% Rule: Only about 10% of the energy available at one trophic level is transferred to the next trophic level. The remaining 90% is lost as heat through metabolic processes, limiting the number of trophic levels in an ecosystem.

  • Pyramid of Energy: A graphical representation of the energy available at each trophic level, typically showing a decrease in energy as you move up the trophic levels.

4. Biogeochemical Cycles

• Water Cycle (Hydrological Cycle):

  • Evaporation: Water from oceans, lakes, and rivers turns into vapor due to solar energy.

  • Transpiration: Water vapor is released from plants into the atmosphere.

  • Condensation: Water vapor cools and forms clouds.

  • Precipitation: Water falls back to Earth as rain, snow, sleet, or hail.

  • Runoff: Water moves across the land, eventually returning to bodies of water.

  • Infiltration: Some water seeps into the ground, replenishing aquifers.

• Carbon Cycle:

  • Photosynthesis: Plants take in carbon dioxide (CO2) and convert it into glucose.

  • Respiration: Organisms release CO2 back into the atmosphere through respiration.

  • Decomposition: Dead organisms are broken down by decomposers, releasing carbon back into the soil and atmosphere.

  • Fossil Fuels: Over millions of years, carbon from dead organisms can be stored in fossil fuels. Burning fossil fuels releases stored carbon as CO2.

  • Ocean Uptake: Oceans absorb CO2, which can form carbonic acid, affecting marine life.

• Nitrogen Cycle:

  • Nitrogen Fixation: Conversion of atmospheric nitrogen (N2) into ammonia (NH3) by bacteria in the soil or through industrial processes.

  • Nitrification: Conversion of ammonia into nitrate (NO3-) by nitrifying bacteria.

  • Assimilation: Plants absorb nitrates from the soil and use them to build proteins and nucleic acids.

  • Ammonification: Decomposition of organic nitrogen into ammonia by decomposers.

  • Denitrification: Conversion of nitrates back into nitrogen gas (N2) by denitrifying bacteria, releasing it back into the atmosphere.

• Phosphorus Cycle:

  • Weathering of Rocks: Phosphorus is released from rocks through weathering and is absorbed by plants from the soil.

  • Assimilation: Plants take up phosphorus and use it in DNA, RNA, and ATP.

  • Decomposition: When organisms die, decomposers return phosphorus to the soil.

  • Sedimentation: Phosphorus can be deposited as sediment in bodies of water, eventually forming new rocks over geological time scales.

5. Population Ecology

• Population Growth:

  • Exponential Growth (J-shaped curve): Occurs when resources are abundant, leading to a rapid increase in population size. This growth is unsustainable as it eventually leads to resource depletion.

  • Logistic Growth (S-shaped curve): Occurs when population growth slows as it reaches the carrying capacity (K) of the environment, the maximum population size that the environment can support indefinitely.

• Carrying Capacity (K):

  • Definition: The maximum number of individuals of a particular species that an environment can sustain over the long term, given the availability of resources such as food, water, and space.

  • Factors Influencing Carrying Capacity: Availability of resources, competition, predation, disease, and environmental conditions.

• Factors Influencing Population Size:

  • Density-Dependent Factors: These factors have a greater impact as population density increases. Examples include competition for resources, predation, disease, and waste accumulation.

  • Density-Independent Factors: These factors affect population size regardless of density.

Chapter 3

Introduction to Biodiversity

Definition and Importance of Biodiversity

Biodiversity (short for biological diversity) refers to the variety of life on Earth at all levels, including genes, species, and ecosystems. It is a crucial component of Earth's natural systems, providing essential ecosystem services such as air purification, water filtration, climate regulation, and food production.

Importance of Biodiversity:

1. Ecological Stability: Diverse ecosystems are more resilient to environmental changes and disturbances. They can recover faster from events like natural disasters or disease outbreaks.

2. Ecosystem Services: Biodiversity supports processes such as pollination, nutrient cycling, and water purification, which are essential for life.

3. Food Security: Many plants, animals, and microorganisms contribute to global food systems. Genetic diversity in crops and livestock ensures better adaptation to environmental changes.

4. Medical and Pharmaceutical Benefits: Many medicines are derived from plants, animals, and microorganisms. For example, penicillin comes from fungi, and the Madagascar periwinkle plant has compounds used to treat cancer.

5. Cultural and Aesthetic Value: Many cultures and traditions have deep connections to biodiversity through spiritual beliefs, art, and recreation.

Levels of Biodiversity

Biodiversity is classified into three main levels:

1. Genetic Diversity

Genetic diversity refers to the variety of genes within a species. It allows populations to adapt to changing environments and resist diseases.

• Example: Different breeds of dogs, or genetic variations in crops like rice and wheat, which help them survive in different climates.

Why is genetic diversity important?

• It enhances a species’ ability to adapt to environmental changes (e.g., climate change, diseases).

• Populations with low genetic diversity (e.g., cheetahs) are more vulnerable to extinction due to inbreeding and genetic diseases.

2. Species Diversity

Species diversity refers to the variety of species within an ecosystem or on Earth. It is measured in terms of:

• Species richness (the number of species in a given area).

• Species evenness (the relative abundance of species in an ecosystem).

Example: A rainforest has high species diversity compared to a desert, as it supports thousands of species of plants, animals, fungi, and microorganisms.

Why is species diversity important?

• Each species has a role in the ecosystem (producers, consumers, decomposers).

• Higher species diversity leads to greater ecosystem resilience.

• The loss of one species can have cascading effects (e.g., loss of pollinators affecting plant reproduction).

3. Ecosystem Diversity

Ecosystem diversity refers to the variety of ecosystems in a given region or across the planet. Different ecosystems provide different habitats, which support diverse species.

Examples of ecosystems:

• Terrestrial ecosystems: Forests, grasslands, deserts, tundra.

• Aquatic ecosystems: Freshwater (rivers, lakes), marine (oceans, coral reefs).

Why is ecosystem diversity important?

• It maintains ecological balance by supporting different species.

• Different ecosystems provide various resources such as food, water, and medicine.

• Loss of ecosystems (e.g., deforestation of rainforests) leads to habitat destruction and species extinction.

Hotspots of Biodiversity

A biodiversity hotspot is a region that is rich in species diversity but also highly threatened by human activities. These areas contain a large number of endemic species (species found nowhere else).

To qualify as a biodiversity hotspot, a region must:

1. Have at least 1,500 species of vascular plants as endemics.

2. Have lost at least 70% of its original vegetation due to human activities.

Examples of Biodiversity Hotspots:

1. Amazon Rainforest (South America) – Home to 10% of the world’s known species.

2. Coral Triangle (Southeast Asia) – The world’s richest marine biodiversity, with over 500 coral species.

3. Madagascar and the Indian Ocean Islands – 90% of species are endemic.

4. Himalayas (Asia) – A diverse range of flora and fauna, including the snow leopard.

5. Sundaland (Indonesia, Malaysia, Thailand, etc.) – Includes Borneo and Sumatra, rich in orangutans and tigers.

Why are biodiversity hotspots important?

• They contain a high number of unique species that cannot be found anywhere else.

• They are under severe threat due to deforestation, urbanization, and climate change.

• Conservation efforts focus on protecting these areas to prevent mass extinctions.

Measuring Biodiversity

Measuring biodiversity is crucial for understanding ecosystem health, tracking changes over time, and identifying areas that need conservation efforts. There are different methods to measure biodiversity, primarily focusing on species richness, species evenness, and diversity indices.

Species Richness and Evenness

Species Richness

Species richness refers to the total number of species present in a given ecosystem or area. It is a simple measure of biodiversity.

Example:

• A rainforest with 50 different species of trees has higher species richness than a grassland with 10 species of plants.

Limitations of species richness:

• It does not take into account the abundance of each species.

• A habitat with 50 species, but one species dominating 95% of the population, may not be truly diverse.

2. Species Evenness

Species evenness refers to the relative abundance of different species in an ecosystem. It measures how evenly individuals are distributed among the species present.

Example:

• Ecosystem A:

  • 50 deer, 50 rabbits, 50 foxes → High species evenness (similar numbers of individuals in each species).

• Ecosystem B:

  • 145 deer, 3 rabbits, 2 foxes → Low species evenness (one species dominates the population).

A high species evenness means that all species in an ecosystem are present in similar proportions, contributing to a more stable ecosystem.

Biodiversity is highest when both species richness and species evenness are high.

Simpson’s Diversity Index (SDI)

Simpson’s Diversity Index (D) is a mathematical formula used to measure biodiversity by considering both species richness and species evenness.

Formula for Simpson’s Diversity Index:

D=1−∑(nN)2D

Where:

• n = number of individuals of a particular species

• N = total number of individuals of all species

• Σ = sum of all values

Interpreting the Index:

• D = 1 → High biodiversity (many species, evenly distributed).

• D = 0 → Low biodiversity (few species or one dominant species).

Higher D values indicate greater biodiversity.

Simpson’s Index is useful because it accounts for both species richness and evenness, giving a more complete picture of an ecosystem’s diversity.

Methods for Measuring Biodiversity

Scientists use different techniques to measure biodiversity in various ecosystems:

1. Quadrat Sampling (for plants and slow-moving organisms)

• A quadrant (a square frame of a fixed size, e.g., 1m²) is randomly placed in a study area.

• The number of different species and their abundance are recorded.

• Multiple quadrats are sampled, and an average is calculated.

Advantages: Simple, cost-effective, useful for estimating plant diversity.
Disadvantages: May not be representative if species distribution is uneven.

2. Transect Sampling (for measuring biodiversity along a gradient)

• A transect line (a rope or measuring tape) is placed across a habitat.

• Species are recorded at regular intervals along the line.

• Useful for studying biodiversity changes across different environmental conditions (e.g., from a riverbank to a dry area).

Advantages: Useful for studying how biodiversity changes across landscapes.
Disadvantages: Time-consuming, may not capture all species.

3. Mark-Recapture Method (for mobile species like animals, fish, and insects)

• Animals are captured, marked (tagged), and released.

• After some time, another sample is captured. The proportion of marked individuals in the second sample is used to estimate population size.

Advantages: Useful for studying populations of moving organisms.
Disadvantages: Assumes marked individuals mix randomly in the population; capturing may stress animals.

4. DNA Barcoding (for identifying species using genetics)

• Scientists extract DNA from organisms and compare sequences to a database.

• Helps identify species that are difficult to distinguish visually (e.g., bacteria, fungi, insects).

Advantages: Highly accurate, can detect new or cryptic species.
Disadvantages: Expensive, requires lab equipment and expertise.

5. Remote Sensing and Camera Traps (for monitoring large areas and elusive species)

• Drones, satellites, and remote cameras help track biodiversity in difficult-to-access regions like rainforests or deep-sea ecosystems.

• Used for tracking deforestation, illegal poaching, and endangered species.

Advantages: Allows for large-scale monitoring, non-invasive.
Disadvantages: High cost, may not detect all species.

Threats to Biodiversity

Biodiversity is under severe threat from human activities and natural processes. The five main threats to biodiversity are habitat destruction, invasive species, climate change, pollution, and overexploitation. These threats often interact, making their effects even more severe.

Habitat Destruction, Fragmentation, and Degradation

a) Habitat Destruction

Habitat destruction occurs when natural environments are cleared, converted, or severely altered for human activities such as agriculture, urbanization, and industrialization.

Causes of Habitat Destruction:

• Deforestation for logging, farming, and cattle ranching (e.g., Amazon rainforest destruction).

• Urban expansion leading to the replacement of natural areas with roads, buildings, and factories.

• Wetland drainage for agriculture and development.

• Coral reef destruction due to coastal development, pollution, and ocean acidification.

Consequences:

• Loss of species that depend on these habitats.

• Disruption of ecosystems, affecting food chains and ecosystem services.

• Reduced carbon storage in forests, worsening climate change.

Example:

• Amazon Rainforest: Large-scale deforestation for soy farming and cattle ranching has led to habitat loss for species like jaguars and macaws.

b) Habitat Fragmentation

Habitat fragmentation occurs when large, continuous habitats are broken into smaller, isolated patches due to roads, urban development, and agricultural expansion.

Consequences:

• Limits migration and breeding by creating barriers between animal populations.

• Increases inbreeding in small populations, reducing genetic diversity.

• Creates edge effects, where habitat edges experience different conditions (e.g., increased predation, temperature shifts).

Example:

• Highways dividing forests prevent animals like tigers and elephants from roaming freely, reducing their genetic pool.

c) Habitat Degradation

Even if a habitat is not completely destroyed, it can be degraded through pollution, invasive species, or climate change.

Examples of Degradation:

• Soil erosion from overgrazing.

• Water pollution from industrial waste and pesticides.

• Coral bleaching due to rising ocean temperatures.

2. Invasive Species

Invasive species are non-native organisms that are introduced to new ecosystems, often causing harm to native species and ecosystems. They can outcompete, prey on, or spread diseases to native species.

How do invasive species spread?

• Accidental introduction (e.g., zebra mussels from ship ballast water).

• Deliberate introduction (e.g., cane toads introduced to Australia to control pests but became a major problem).

Effects of Invasive Species:

• Outcompete native species for food and resources.

• Introduce new diseases that native species cannot resist.

• Disrupt entire ecosystems by altering food chains.

Examples of Invasive Species:

1. Kudzu (USA): A fast-growing vine from Asia that outcompetes native plants.

2. Burmese Python (Florida Everglades): A predator that has drastically reduced mammal populations.

3. Asian Carp (USA rivers): Disrupts aquatic ecosystems by outcompeting native fish.

Climate Change

Climate change is one of the biggest long-term threats to biodiversity, affecting temperature, weather patterns, and sea levels.

Effects on Biodiversity:

• Changing habitats: Warming temperatures force species to migrate (e.g., polar bears losing sea ice).

• Coral bleaching: Higher ocean temperatures cause corals to expel symbiotic algae, leading to reef die-offs.

• More extreme weather: Hurricanes, droughts, and wildfires destroy habitats.

• Ocean acidification: CO₂ dissolves into seawater, making it more acidic and harming marine life.

Examples:

• Polar bears (Arctic): Loss of sea ice reduces their hunting grounds.

• Coral reefs (Great Barrier Reef): Warming seas cause coral bleaching, threatening marine biodiversity.

Pollution

Pollution degrades ecosystems and directly harms wildlife. There are several major types:

a) Air Pollution

• Burning fossil fuels releases CO₂ (climate change) and sulfur dioxide (acid rain).

• Acid rain damages forests and aquatic ecosystems.

• Smog reduces plant photosynthesis.

b) Water Pollution

• Oil spills kill marine life.

• Plastic pollution harms sea animals (e.g., turtles mistake plastic bags for jellyfish).

• Industrial waste and pesticides poison freshwater habitats.

c) Soil Pollution

• Excess fertilizers cause eutrophication, where algal blooms deplete oxygen and kill aquatic life.

• Toxic waste from mining and industry affects plants and microorganisms.

Example:

• Deepwater Horizon Oil Spill (2010): Killed marine life and damaged Gulf of Mexico ecosystems.

Overexploitation (Hunting, Fishing, Deforestation)

Overexploitation occurs when humans extract resources at a rate faster than they can be replenished.

a) Overhunting and Poaching

• Targeting species for food, medicine, or trade.

• Leads to population collapse and extinction.

• Poaching is illegal hunting for high-value products.

Examples:

• African Elephants: Poached for ivory.

• Tigers: Killed for skins and traditional medicine.

b) Overfishing

• Unsustainable fishing methods (trawling, longlining) deplete fish stocks and destroy habitats.

• Bycatch (unintentional capture of non-target species) kills dolphins, turtles, and seabirds.

Examples:

• Cod in the North Atlantic: Overfished to near extinction.

• Sharks: Killed for shark fin soup, disrupting marine ecosystems.

c) Deforestation

• Large-scale clearing of forests for agriculture, timber, and urbanization.

• Reduces oxygen production and destroys carbon sinks, worsening climate change.

Example:

• Amazon Rainforest: Deforestation for cattle farming is destroying global biodiversity.

Conservation of Biodiversity

Biodiversity conservation aims to protect species, habitats, and ecosystems from extinction and degradation. There are two main approaches: in situ (on-site) conservation and ex situ (off-site) conservation.

In Situ Conservation (Protecting Species in Their Natural Habitat)

In situ conservation means protecting species within their natural environment. This method helps preserve not only individual species but also entire ecosystems.

Examples of In Situ Conservation:

• Protected Areas (National Parks, Nature Reserves, Wildlife Sanctuaries)

• Legislation to Protect Species

• Restoration of Degraded Habitats

Protected Areas (National Parks, Wildlife Reserves, Nature Reserves)

Governments and organizations set aside land to protect ecosystems and wildlife. These areas are often strictly regulated to prevent habitat destruction, hunting, and pollution.

Examples:

1. Yellowstone National Park (USA): Protects wolves, bison, and grizzly bears.

2. Amazon Rainforest Reserves: Prevent large-scale deforestation and preserve indigenous species.

3. Sundarbans (India & Bangladesh): Home to the Bengal tiger and mangrove forests.

Advantages:

• Species continue to evolve naturally in their ecosystem.

• Maintains ecosystem interactions (predator-prey relationships, pollination, seed dispersal).

• Protects multiple species at once, not just one endangered species.

Disadvantages:

• Large areas are required, which may not always be available.

• Difficult to prevent poaching, illegal logging, or habitat destruction.

• Some species may still decline due to external threats like climate change.

Legislation and Conservation Laws

Governments can pass laws to protect endangered species from hunting, habitat destruction, and trade.

Examples:

• Endangered Species Act (USA): Protects threatened species like the Bald Eagle.

• EU Birds and Habitats Directive: Ensures conservation of natural habitats and wild species.

Advantages:

• Prevents hunting and habitat destruction.

• Encourages sustainable development.

Disadvantages:

• Difficult to enforce in remote areas.

• Needs international cooperation to stop illegal wildlife trade.

Ex Situ Conservation (Protecting Species Outside Their Natural Habitat)

Ex situ conservation involves removing species from their natural habitats and placing them in controlled environments to protect them from extinction.

Examples of Ex Situ Conservation:

• Zoos and Captive Breeding Programs

• Botanical Gardens

• Seed Banks

Zoos and Captive Breeding Programs

Zoos play an essential role in conserving endangered species by breeding them in captivity and sometimes reintroducing them into the wild.

Examples:

• Giant Panda (China): Conservation efforts in zoos helped increase the wild population.

• California Condor (USA): Once only 27 remained; captive breeding brought them back from extinction.

Advantages:

• Protects species from poaching, habitat loss, and environmental threats.

• Helps increase population numbers.

• Can be used for education and research.

Disadvantages:

• Expensive to maintain.

• Animals may not survive when reintroduced into the wild.

• Some species cannot reproduce well in captivity.

Botanical Gardens

Botanical gardens grow and maintain plant species, often focusing on rare and endangered plants.

Examples:

• Royal Botanic Gardens (UK): Home to thousands of plant species.

• Singapore Botanic Gardens: Conserves tropical plant species.

Advantages:

• Preserves genetic diversity of plants.

• Prevents rare plant species from going extinct.

Disadvantages:

• Cannot fully replicate natural habitats.

• Limited space for large trees and forest ecosystems.

Seed Banks

Seed banks store seeds under controlled conditions for future use in reforestation, habitat restoration, and agricultural biodiversity conservation.

Examples:

• Svalbard Global Seed Vault (Norway): Stores over a million seed varieties to prevent crop extinction.

• Millennium Seed Bank (UK): Conserves seeds from around the world.

Advantages:

• Protects plant species from extinction due to climate change or disasters.

• Ensures crop diversity for future food security.

Disadvantages:

• Seeds may not germinate after long storage.

• Does not protect plant-pollinator relationships or natural ecosystems.

Endangered Species and the IUCN Red List

The International Union for Conservation of Nature (IUCN) maintains the Red List, which classifies species based on their risk of extinction.

IUCN Red List Categories:

1. Extinct (EX): No individuals left (e.g., Dodo, Passenger Pigeon).

2. Extinct in the Wild (EW): Survives only in captivity (e.g., Scimitar-horned Oryx).

3. Critically Endangered (CR): Extremely high risk of extinction (e.g., Amur Leopard).

4. Endangered (EN): High risk of extinction (e.g., Blue Whale, Bengal Tiger).

5. Vulnerable (VU): At risk but not yet endangered (e.g., Polar Bear).

6. Near Threatened (NT): May soon be at risk (e.g., Monarch Butterfly).

7. Least Concern (LC): No immediate threat (e.g., Pigeon, House Sparrow).

Uses of the Red List:

• Guides conservation efforts and funding.

• Helps governments create protective laws.

• Raises awareness about endangered species.

Limitations:

• Not all species are well studied.

• Data collection can be difficult in remote areas.

Role of International Organizations in Conservation

Several international organizations work to protect biodiversity at a global level.

World Wildlife Fund

A global NGO focused on conservation, climate change, and sustainable resource use.

Key Projects:

• Protecting tigers in India and Nepal.

• Preserving rainforests in the Amazon and Congo.

Strengths: Large global influence, funding for conservation projects.
Weaknesses: Relies on donations, limited enforcement power.

Convention on International Trade in Endangered Species

A global agreement regulating trade in endangered species to prevent overexploitation.

Key Actions:

• Bans ivory trade to protect elephants.

• Controls trade in exotic pets like parrots and tortoises.

Strengths: Legally binding treaty with international cooperation.
Weaknesses: Enforcement is difficult, illegal trade still exists.

International Union for Conservation of Nature

The IUCN maintains the Red List and advises governments on conservation policies.

Key Actions:

• Classifies species based on extinction risk.

• Develops conservation guidelines.

Strengths: Provides scientific data and influences conservation policies.
Weaknesses: No direct power to enforce laws.

Conservation Strategies and Sustainable Management

Biodiversity conservation requires different approaches to protect species, habitats, and ecosystems. These include species-based conservation, habitat conservation, sustainable resource management, and ecotourism.

Species-Based Conservation

Species-based conservation focuses on protecting individual species that are at risk of extinction through methods like captive breeding, reintroduction programs, and genetic management.

Captive Breeding Programs

Captive breeding involves breeding endangered species in controlled environments like zoos or wildlife centers to increase their population and prevent extinction.

How it works:

• Scientists select breeding pairs to maximize genetic diversity.

• Animals are bred in captivity and raised with minimal human interaction to prepare them for the wild.

• The goal is to reintroduce the species into its natural habitat.

Examples:

1. California Condor (USA): In 1987, only 27 remained in the wild. Captive breeding increased their numbers, and now over 500 exist.

2. Arabian Oryx: Extinct in the wild in the 1970s but reintroduced through breeding programs.

3. Giant Panda (China): Zoos and breeding centers helped increase their population, leading to their classification improving from "Endangered" to "Vulnerable."

Advantages:

• Prevents immediate extinction.

• Can help increase population numbers.

• Allows for genetic diversity management to avoid inbreeding.

Disadvantages:

• Some animals struggle to survive in the wild after being raised in captivity.

• Expensive and requires long-term funding.

• Limited space in breeding programs.

Reintroduction Programs

Reintroduction involves releasing captive-bred or rescued animals back into their natural habitat to restore wild populations.

Steps in a reintroduction program:

1. Habitat assessment – Ensuring the habitat is suitable for the species.

2. Pre-release training – Teaching animals survival skills (hunting, avoiding predators).

3. Gradual release – Some animals are first kept in semi-wild enclosures before full release.

4. Post-release monitoring – Scientists track survival rates and adaptation.

Examples:

1. Wolves in Yellowstone National Park (USA): Gray wolves were reintroduced in the 1990s after being hunted to extinction in the area. Their return restored ecosystem balance by controlling deer populations.

2. European Bison (Poland): Successfully bred in captivity and reintroduced into forests.

3. Black-Footed Ferret (USA): Once considered extinct, now thriving after reintroduction efforts.

Advantages:

• Restores ecosystems by bringing back keystone species.

• Helps increase wild populations.

• Reduces risk of losing species permanently.

Disadvantages:

• Some animals struggle to adapt after reintroduction.

• Requires large, protected areas for released animals.

• Threats like poaching or habitat destruction may still exist.

Habitat Conservation and Ecosystem Management

Protecting entire habitats and ecosystems is often more effective than focusing on single species. This approach maintains all species within a balanced ecosystem.

Protected Areas (National Parks, Wildlife Reserves, Marine Protected Areas)

Protected areas are legally designated regions where human activity is restricted to protect biodiversity.

Examples:

• Yellowstone National Park (USA) – Protects grizzly bears, wolves, and bison.

• Great Barrier Reef Marine Park (Australia) – Protects coral reef ecosystems.

• Maasai Mara Reserve (Kenya) – Supports lions, elephants, and wildebeest.

Advantages:

• Protects entire ecosystems, not just one species.

• Encourages ecotourism (which generates funds for conservation).

• Supports natural ecological processes like migration and predation.

Disadvantages:

• Requires strong law enforcement to prevent poaching.

• Some species still face threats from climate change.

• Local communities may lose land or access to resources.

Habitat Restoration

Habitat restoration involves repairing damaged ecosystems to bring back lost biodiversity.

Examples:

1. Reforestation (Tree Planting): Replanting forests to restore lost habitats.

2. Coral Reef Restoration: Using artificial reefs to help coral regrow.

3. Wetland Restoration: Reintroducing native plants to improve water filtration.

Advantages:

• Helps species recover naturally.

• Improves ecosystem services (clean water, air purification).

• Supports carbon sequestration, reducing climate change impact.

Disadvantages:

• Can take decades for full recovery.

• Expensive and labor-intensive.

• Restored areas may still be vulnerable to future destruction.

Case Studies in Conservation

Conservation efforts can be classified into success stories (where biodiversity has been restored or protected) and failures (where conservation efforts have been ineffective). Below are key case studies from around the world.

Conservation Success Stories

The Reintroduction of the Gray Wolf (Yellowstone National Park, USA)

Background:

Gray wolves were eradicated from Yellowstone National Park in the early 20th century due to hunting and conflicts with ranchers. This led to an overpopulation of elk, which in turn overgrazed the land and caused habitat degradation.

Conservation Efforts:

• In 1995, wolves were reintroduced to Yellowstone from Canada.

• This restored the natural predator-prey balance.

Results:

Positive effects on the ecosystem:

• Elk population controlled: Wolves hunted elk, reducing their overgrazing.

• Habitat recovery: More vegetation (aspen, willow) grew back, leading to an increase in biodiversity.

• Increased biodiversity: Beavers, birds, and fish returned as plant life improved.

Key Lesson: Predators play a crucial role in maintaining ecosystem balance.

The Recovery of the Bald Eagle (USA)

Background:

• Bald eagles faced near extinction in the mid-1900s due to DDT pesticide use (which weakened their eggshells) and hunting.

• The species was placed on the Endangered Species List in 1967.

Conservation Efforts:

• DDT was banned in 1972 after research linked it to reproductive failure in birds.

• Hunting laws were strengthened under the Endangered Species Act (1973).

• Habitat protection and breeding programs were introduced.

Results:

• Population recovery: From 417 nesting pairs (1963) to over 10,000 pairs today.

• Removed from the Endangered Species List in 2007.

Key Lesson: Government action and legal protection can effectively save species from extinction.

The Giant Panda (China) – Captive Breeding & Habitat Protection

Background:

• The giant panda population declined due to habitat loss, poaching, and low reproductive rates.

• By the 1980s, only 1,200 pandas remained in the wild.

Conservation Efforts:

• Establishment of nature reserves in China.

• Captive breeding programs at conservation centers like the Chengdu Panda Base.

• Ban on panda hunting and stricter conservation laws.

Results:

• Population increase to over 1,800 pandas today.

• IUCN status changed from "Endangered" to "Vulnerable" in 2016.

• Successful reintroduction of pandas into the wild.

Key Lesson: A combination of in situ (habitat protection) and ex situ (captive breeding) strategies is effective.

Marine Conservation – The Great Barrier Reef (Australia)

Background:

• The Great Barrier Reef, the world’s largest coral reef system, has faced serious threats from climate change, coral bleaching, pollution, and overfishing.

Conservation Efforts:

• Marine protected areas (MPAs) were established to reduce fishing and tourism impacts.

• Coral restoration projects are being implemented.

• Reduction of agricultural runoff to prevent pollution.

Results:

• Coral restoration projects show promise.

• Stronger protection laws have reduced damage.

• Challenges remain due to climate change.

Key Lesson: Marine conservation requires global efforts to combat climate change.

Conservation Failures

The Extinction of the Northern White Rhino

Background:

• The northern white rhinoceros was heavily poached for its horn, which is used in traditional medicine.

• Habitat destruction and civil wars in Africa worsened the situation.

Failed Conservation Efforts:

• Despite being protected in reserves, poaching continued due to weak enforcement.

• Captive breeding attempts failed because of low genetic diversity.

Results:

• Only 2 northern white rhinos remain (both female), making natural reproduction impossible.

• Declared functionally extinct in 2018.

Key Lesson: Strict enforcement and anti-poaching measures must be in place before a species’ population drops too low.

The Collapse of the Atlantic Cod Fishery (Canada)

Background:

• Overfishing led to the near collapse of Atlantic cod populations off the coast of Canada.

• Despite warnings from scientists, fishing quotas were too high, leading to unsustainable practices.

Failed Conservation Efforts:

• A moratorium (ban) on cod fishing was introduced in 1992, but the damage was already done.

• Cod populations failed to recover as expected due to ecological shifts.

Results:

• The cod fishery collapsed, leading to massive job losses in Canada.

• Cod populations remain low today, even after 30+ years of protection.

Key Lesson: Preventative conservation is crucial—waiting too long can lead to irreversible damage.

The Deforestation of the Amazon Rainforest

Background:

• The Amazon rainforest is the world’s largest tropical rainforest, home to millions of species.

• Deforestation rates have increased due to logging, agriculture (soy, cattle), and fires.

Failed Conservation Efforts:

• Protection laws exist, but illegal logging and weak enforcement continue.

• Deforestation increased under certain governments that prioritized economic growth over conservation.

Results:

• Over 17% of the Amazon has been lost.

• Continued deforestation threatens global biodiversity and worsens climate change.

Key Lesson: Conservation requires strong political commitment and enforcement.

What Can We Learn from These Case Studies?

Conservation Success Factors:

• Strong laws and enforcement (e.g., Bald Eagle recovery).

• Habitat protection (e.g., Giant Panda reserves).

• Captive breeding and reintroduction (e.g., Wolves in Yellowstone).

Common Causes of Conservation Failures:

• Weak law enforcement (e.g., Rhino poaching).

• Delays in action (e.g., Atlantic Cod collapse).

• Ignoring ecological warning signs (e.g., Amazon deforestation).

Chapter 4

Topic 4: Water

IB Environmental Systems and Societies (HL) - Topic 4: Water

4.1 - Water Systems

• Hydrological cycle (The Water Cycle): Interconnected system where water moves through the atmosphere while going through different phases

• Water moves into storages and flows throughout the cycle

• Storages: Where water is stored when it is not actively moving through the water cycle. The time spent in storages greatly varies.

  • Examples of storages:

    • Organisms

    • Soil

    • Oceans

    • Water vapor/the atmosphere

    • Surface waters

    • Ice caps/glaciers

    • Aquifers

• Flows: When water moves from one storage to another via flow routes. Can either be transformations (change in state) or transfers (change in location)

  • Examples of flow transformations:

    • Evaporation

      • Liquid water becomes gas after being heated, and removes salt and other metals/minerals

    • Transpiration

      • Process where plants absorb water through roots and release water vapor through the stomata in their leaves

    • Evapotranspiration

      • Combined process of both evaporation and transpiration

    • Condensation

      • Gas water becomes liquid again because it has cooled, which forms clouds or dew

    • Sublimation

      • When water directly becomes gas, after being a solid, without going through a liquid state first

    • Freezing/melting

  • Examples of flow transfers:

    • Advection

      • When water vapor/droplets/clouds are moved by the wind

    • Flooding

    • Precipitation

    • Surface run-off

    • Infiltration

      • When water from the surface seeps through the soil layers and becomes groundwater

    • Percolation

      • When water moves downwards through soil/rocks after infiltration, eventually reaching groundwater reservoirs

    • Groundwater flow

    • Current/stream flow

    • Absorption

• Water cycle is driven by energy from the sun

  • In its most basic form, the cycle follows three steps:

1. The sun’s heat will evaporate the water in storages (ex. Lakes, oceans)

2. The water vapor cools and condenses, and then falls back to the Earth as precipitation (ex. Rain, snow)

3. Runoff from the precipitation will eventually find its way back to storages

• Freshwater only makes up 2.5% of the Earth’s water

  • In some storages (such as groundwater), water would be considered non-renewable because it is renewed too slow

• Human impacts on the Water Cycle:

• Surface runoff and infiltration can be impacted by human activities, such as

  • Agriculture:

    • Disruption of soil and usage of pesticides/fertilizers can cause contaminated runoff/groundwater

  • Deforestation:

    • The lack of trees causes more soil erosion and nearby water contamination because there are no trees to filter the runoff

    • Decreases transpiration, which reduces moisture in the air

  • Burning fossil fuel:

    • Increased temperatures cause more evaporation/melting, which alters the natural balance of the cycle

• Ocean circulation system

• Ocean conveyor belt:

  • Constantly moving system that moves water around, driven by differences in salinity and temperature

  • Results in the movement of nutrients and heat, which is essential for regulating local weather and global climate, and for the health of marine ecosystems

• El Niño: Climate pattern where the surface waters of the eastern Pacific will periodically become warmer, which causes more rain and hotter temperatures

• La Niña: Climate pattern that is almost the opposite of El Niño, where eastern Pacific surface water temperatures become colder

4.2 - Water access, use and security

• Access to clean freshwater

• Varies greatly from place to place

• Proper infrastructure to make water safe for drinking/available to everyone is very expensive, which

• Water-related diseases cause millions of deaths each year, especially in developing countries

  • Infections caused by drinking or coming into contact with contaminated water examples: cholera, ringworm, polio, typhoid

  • Infections caused by insects/parasites that breed/spend most of their life in water examples: Guinea worm, bilharzia, malaria, dengue fever

• Distribution of water

• Certain countries do not have a proper source of water and need to look outside their borders for water

  • This can lead to conflicts over the control of water resources

• Some countries do not receive adequate amounts of rainfall due to their climate, which can lead to water stress and scarcity

• Water stress: When the demand for water is far greater than the supply for an extended period, or when the quality of the water supply makes it unusable

  • Climate change accelerates this problem.

• Demand for water is increasing

• The agriculture industry - the biggest use of water, especially in developing countries where they cannot afford to import food

• Additionally, a shift to more meat in diets results in more water consumption than any other form of agriculture

• Growing populations, an increase in the standard of living, and more people living in urban areas also increases demand for water

• Increasing water sources and decreasing demand to alleviate water access issues

  • Reservoirs

• Lakes that are naturally or artificially created to collect and store water

• Desalination

  • Making saltwater suitable for drinking, very expensive process that is usually only done in countries that are in dry regions and have access to lots of cheap energy

• Artificial recharge

  • Used to replenish water in aquifers by either pumping water from rivers into the aquifers or by intercepting runoff and collecting it in the aquifers

• Increasing water efficiency in residential homes

  • Using appliances that use less water

• Using different irrigation methods in agriculture

  • Ex. Drip irrigation

• Promoting using less water to the general public or offering economic incentives

4.3 - Aquatic Food Production Systems

• Growth in population results in a higher demand for aquatic food sources

  • Human population is growing very quickly, resulting in a higher demand for food from aquatic animals

• Most of the photosynthesis done on Earth comes from phytoplankton

  • Primary producer: An organism that creates their own energy through photosynthesis

• Energy from phytoplankton, a type of primary producer, is the foundation of many ecosystems because of their abundance and ability to create energy, marine ecosystems have high productivity and biodiversity

  • Boundary ecosystems (ecosystems near coastlines/shallow waters) are home to many diverse species

    • This is because the area is shallow enough that lots of light can reach the bottom, which allows primary producers, and eventually consumers, to thrive

• Fishing equipment and techniques have changed over time, leading to decreased fish populations and harm to marine habitats

  • Before the rapid development of fishing technology, fishers were limited in their capacity to harvest fish

    • Improvements to boats, gear, satellite technology and nets have led to increased supply of seafood

      • Unfortunately, the demand is so great that overfishing of certain areas has become a big issue

• Aquaculture has extreme benefits and drawbacks, making it very controversial

  • Aquaculture: controlled farming of aquatic organism that is essential to meeting the demand for seafood, one of the fastest growing methods of food production in the world

    • Benefits:

      • Supports local economies

      • Provides important nutrients to people’s diets

    • Drawbacks:

      • Habitat destruction and community displacement

      • Spread of disease and pollution

• Ethical issues from fishing have become increasingly concerning

  • Prevention of overfishing to protect marine communities

    • Marine ecosystems are extremely important to the health of the organisms that live in them and to the planet

      • Overfishing reduces biodiversity, which damages the environment

  • Reducing the contamination caused by the aquatic food industry

    • Pollution harms the health of aquatic animals and humans, which is a threat to local life and food safety.

  • International and local legislation have been passed in order to stop the damage done

4.4 - Water Pollution

• Sources of water pollution:

• Industrial waste:

  • Toxic chemicals and metals that come from industries that lack proper waste management can be poisonous to local animals

    • Examples:

      • Nitrates

      • Mercury

      • Lead

• Wastewater/sewage:

  • Wastewater/sewage that is produced by households, chemically treated and then released into the environment

    • Chemicals and pathogens can cause health issues to marine life and humans

  • Also, leaks in sewage lines can contaminate groundwater

• Mining activities:

  • Toxic elements that contain chemicals are extracted by mining, and can reach nearby bodies of water and harm the local ecosystems

• Marine dumping:

  • In certain places, residential garbage is disposed into the ocean, which can take years to decompose, harming the marine ecosystem

• Oil spills:

  • Accidental oil leakage is poisonous and does not dissolve into the water, which damages the health of birds and all marine organisms living in the area

• Fossil fuel burning:

  • Ash that comes from burning coal or oil contains toxic chemicals that can mix with water vapor in the atmosphere and result in acid precipitation

  • Can also contribute to global warming

• Chemicals and metals:

  • Pesticides, and fertilizers used in agriculture can reach nearby bodies of water, via rain or runoff, and be harmful to local plants and animals

• Global warming:

  • An increase in water temperature can kill marine species because their bodies cannot handle unnatural changes in conditions

• Radioactive waste:

  • Nuclear energy: A type of energy that is produced by nuclear fission or fusion, which uses an element called uranium

  • Uranium is extremely toxic and must be disposed of properly, or else entire ecosystems can be destroyed

• Suspended matter:

  • Particulate matter: Material that is too big to dissolve and becomes suspended in water

  • This matter eventually settles at the bottom of bodies of water and can be dangerous to organisms that live on the floor of rivers/lakes

• Microbial pollution:

  • Natural water pollution caused by microorganisms such as bacteria, viruses, and protozoa

    • Can cause illnesses such as cholera and typhoid

• Measurements water quality:

  • Direct measurements: Monitoring the level of pollutants

  • Indirect measurements: Monitoring the effects of the pollutants on the local ecosystem/animals

  • Indicator species: A species whose abundance or lack of abundance can be an indicator of the health of an ecosystem because they are extremely sensitive to changing ecological conditions

  • Types of water quality measurements:

    • Salinity

    • pH

    • Temperature

    • Dissolved oxygen

    • Turbidity

• Biodegradability:

  • When microorganisms, such as bacteria and fungi, break down organic matter into simple inorganic molecules such as water, methane or carbon dioxide

  • Too much organic matter can cause excessive biodegradation, which results in low dissolved oxygen levels

    • Low dissolved oxygen levels can cause many of the local animals to die or migrate

• Biochemical oxygen demand (BOD):

  • Measure of the amount of oxygen bacteria/other microorganisms will need to remove organic waste in water through decomposition

  • Having polluting organic waste in the water results in higher BOD levels because there are many organisms using the water for respiration

• Eutrophication:

  • When lakes, estuaries and coastal waters have high levels of nutrients (nitrogen/phosphorus), there is a massive increase in algae

    • Algae are food for many organisms, so the increase in algae causes an increase in other organisms

    • When those organisms eventually die, there is an increase in organic dead matter and decomposition

    • The increase in respiration needed to decompose the dead matter will require more oxygen than there is available, causing many organisms to die because of lack of oxygen

  • This increase of nutrients is caused by fertilizer runoff

    • The effects the lack of oxygen has on an ecosystem can be catastrophic, including:

      • Large percent of the population dying

      • Loss of biodiversity

      • Dead zones

        • Regions in fresh and saltwater where the oxygen levels are low, which results in there being practically no plants or animals

• Water pollution management:

  • Removing pollutants:

    • Treating sewage water

    • Physically removing algae blooms

    • Pumping mud from eutrophic lakes

  • Reducing amount of pollutants released:

    • Educating the public on reducing activities that pollute

    • Physically preventing pollutants from reaching nearby bodies of water

      • Buffer zone: Zones around sensitive areas, such as water sources, that prevent any pollutants from agricultural land from accidentally reaching it

Chapter 5

Land(IB)

SOIL

Soil is a natural body comprised of solids (minerals and organic matter), liquids, and gasses that form on the land surface, occupy space, and are characterized by one or both of the following:

- Horizons (or layers) that are distinguishable from the initial material as a result of additions, losses, transfers, and transformations of energy and matter

-Or the ability to support rooted plants in a natural environment

1. Soil system storages include organic matter, organisms, nutrients, minerals, air, and water.

2. Transfers of material within the soil, including biological mixing and leaching (minerals dissolved in water moving through the soil), contribute to the organization of the soil.

3. Organic material inputs include leaf litter and inorganic matter from parent material, precipitation, and energy. Outputs include uptake by plants and soil erosion.

4. Transformations include decomposition, weathering, and nutrient cycling.

5. The structure and properties of sand, clay, and loam soils greatly differ. Mineral and nutrient content, drainage, water-holding capacity, air spaces, biota, and potential to hold organic matter are all linked to the ability of the soil to promote primary productivity.

6. The upper limit of soil is the boundary between soil and air, shallow water, live plants, or plant materials that have not begun to decompose. Areas are not considered to have soil if the surface is permanently covered by water too deep (typically more than 2.5 meters) for the growth of rooted plants.

7. The lower boundary that separates soil from the non soil underneath is the most difficult to define. Soil consists of horizons near the Earth's surface that, in contrast to the underlying parent material, have been altered by the interactions of climate, relief, and living organisms over time.

Inorganic Components

• Rock fragments

• Sand

• Silt

• Clay

Organic Components

Living Organisms:

• Bacteria

• Fungi

• Earthworms

Dead organic matter:

• Decaying plants

• Animal remains

• Animal waste (feces)

Soils as Systems

• Soils are dynamic systems within larger ecosystems

• As with any system, soil systems can be simplified by breaking them into the following components:

• Storages

• Flows (input and outputs)

• Transfers (change in location) and transformations (change in chemical nature, state or energy).

Soil Profiles

• Soil profiles develop as a result of long-term interactions within the soil system

• These interactions and processes form distinct layers known as horizons

• These layers vary in composition and characteristics from the surface downward

• This reflects the process of soil formation over time

• Profiles usually transition from organic-rich layers near the surface to more mineral-rich layers deeper down

• These lower layers generally contain more inorganic material

• The development of soil profiles are influenced by factors such as:

• Climate

• Vegetation

• Parent material

• Time

Real-World Examples

• Tropical rainforests:

• Often have thick, organic-rich top soils due to rapid decomposition and high biological activity

• Desert regions:

• Characterized by shallow, mineral-dominated soils with distinct horizons due to low organic matter input and minimal leaching

• Peat soils in boreal forests:

• Soils characterized by thick layers of partially decomposed organic matter (peat)

• This is due to the cold, wet conditions that slow down decomposition rates, resulting in highly acidic and nutrient-poor soils

• Prairie soils in the Great Plains, USA:

• Soils known for their deep, dark topsoil have developed over a millennia

• This is due to the accumulation of organic matter from grassland vegetation and the semi-arid climate

Chapter 6

Atmosphere and climate change (IB)

The Earth's Atmosphere

The Earth's atmosphere is the layer of gases surrounding the Earth, essential for life on the planet. It provides oxygen, protects from harmful ultraviolet radiation, and helps regulate temperature through the greenhouse effect.

Layers of the Atmosphere:

1. Troposphere:

   • This is where all weather phenomena occur (e.g., clouds, storms, and rainfall).

   • Temperature decreases with altitude in this layer.

   • Contains around 75% of the atmosphere’s mass.

2. Stratosphere:

   • Contains the ozone layer, which absorbs harmful UV radiation from the Sun and protects life on Earth.

   • Temperature increases with altitude because the ozone layer absorbs solar radiation.

3. Mesosphere:

   • This layer extends to about 85 km above the Earth.

   • It’s where meteors burn up when they enter the atmosphere.

   • Temperature decreases with altitude in this layer.

4. Thermosphere:

   • Extends from 85 km to about 600 km.

   • The air is very thin, and temperatures increase significantly with altitude.

   • Solar activity (sunspots, solar flares) has a big influence here.

   • This is where the Northern and Southern Lights (Aurora Borealis/Australis) occur due to interactions between solar winds and the Earth's magnetic field.

5. Exosphere:

   • Above 600 km, the atmosphere becomes extremely thin and merges into outer space.

   • This layer contains hydrogen and helium atoms that can escape into space.

Composition of the Atmosphere:

• Nitrogen (78%): It is inert and does not react with other elements under normal conditions, acting as a filler.

• Oxygen (21%): Essential for respiration in animals and plants.

• Argon (0.9%): A noble gas with no significant impact on the atmosphere.

• Carbon Dioxide (0.03%): Vital for photosynthesis in plants but is a major contributor to the greenhouse effect.

• Water Vapor: Its concentration varies between 0-4%, depending on location and weather conditions.

The Greenhouse Effect

The greenhouse effect refers to the trapping of heat in the Earth's atmosphere due to the presence of certain gases. These gases allow sunlight to pass through but prevent some of the heat from escaping into space, warming the planet.

• Incoming Solar Radiation: The Sun emits energy in the form of light (visible radiation) and heat (infrared radiation). This energy passes through the atmosphere and warms the Earth's surface.

• Outgoing Infrared Radiation: The Earth then emits this absorbed energy as infrared radiation, which is absorbed and re-emitted by greenhouse gases like CO2, methane, and water vapor, trapping heat in the atmosphere.

• Enhanced Greenhouse Effect: Human activities, such as burning fossil fuels, deforestation, and industrial activities, have increased the concentration of greenhouse gases, leading to more heat being trapped and global warming.

Climate vs. Weather

• Weather: Refers to short-term atmospheric conditions in a particular location (e.g., daily temperature, humidity, rainfall).

• Climate: Refers to the long-term average of weather conditions over a prolonged period (typically 30 years). The climate can be influenced by factors such as latitude, altitude, ocean currents, and wind patterns.

Key Differences:

• Weather is variable and changes frequently, while climate is stable and predictable over long periods.

• Weather can be experienced on a daily or weekly basis, while climate is more about patterns and averages over decades.

Human Activities Contributing to Climate Change

The rapid increase in greenhouse gases due to human activities is the primary cause of contemporary climate change. Key contributors include:

• Burning of Fossil Fuels:

  • Coal, oil, and natural gas are burned for energy in electricity generation, industry, and transportation, releasing CO2 and other GHGs.

• Deforestation:

  • Trees absorb CO2 for photosynthesis. When forests are cleared for agriculture or urbanization, carbon is released, exacerbating global warming.

• Agriculture:

  • Livestock farming produces methane (a potent GHG), especially from ruminant animals (cattle, sheep).

  • Rice paddies also release methane.

  • Synthetic fertilizers used in agriculture release nitrous oxide (N2O), a greenhouse gas more powerful than CO2.

• Industrial Processes:

  • The production of cement, chemicals, and metals often releases significant amounts of CO2, as well as other industrial gases, such as hydrofluorocarbons (HFCs).

• Waste Management:

  • Landfills emit methane as organic waste decomposes anaerobically (without oxygen).

Impacts of Climate Change

Climate change brings about various physical and environmental changes. Some of these are:

• Rising Global Temperatures:

  • The Earth's average temperature has risen by approximately 1°C since the late 19th century, with significant consequences for ecosystems and human health.

• Melting Ice and Snow:

  • The polar ice caps and glaciers are melting rapidly, contributing to rising sea levels.

• Sea-Level Rise:

  • Rising temperatures cause seawater to expand and ice to melt, raising global sea levels. This threatens coastal regions with flooding, erosion, and loss of land.

• Extreme Weather Events:

  • Increased temperatures can lead to more frequent and severe weather events such as hurricanes, heatwaves, droughts, and floods.

• Ocean Acidification:

  • The ocean absorbs about a quarter of the CO2 emissions, leading to acidification. This harms marine ecosystems, particularly coral reefs and shellfish.

• Loss of Biodiversity:

  • Climate change alters habitats, forcing species to migrate or adapt. Some species, particularly those in sensitive ecosystems (e.g., polar regions), face extinction.

Global Climate Models (GCMs)

Global Climate Models (GCMs) simulate the Earth's climate system and predict future climate conditions based on various scenarios of greenhouse gas emissions.

• Components of GCMs: These models consider factors like solar radiation, GHG concentrations, aerosols, cloud formation, ocean circulation, and land use changes.

• Emission Scenarios: The Intergovernmental Panel on Climate Change (IPCC) uses scenarios called Representative Concentration Pathways (RCPs) to model potential future emissions, ranging from high emissions (RCP8.5) to low emissions (RCP2.6).

• Projections: GCMs predict changes in temperature, precipitation patterns, and sea level rise over different time frames (e.g., 2050, 2100).

Mitigation and Adaptation Strategies

Mitigation focuses on reducing or preventing greenhouse gas emissions, while adaptation involves adjusting to the changes that are already occurring.

Mitigation Strategies:

• Renewable Energy: Transition to energy sources such as solar, wind, hydropower, and geothermal to replace fossil fuels.

• Energy Efficiency: Improve the efficiency of buildings, vehicles, and industrial processes to reduce energy consumption.

• Carbon Capture and Storage (CCS): Capture CO2 emissions from power plants and industrial sites, and store them underground to prevent them from entering the atmosphere.

• Carbon Trading: A market-based approach where countries or companies can trade carbon credits to meet emissions reduction targets.

• Sustainable Land Use: Implement agroforestry, regenerative agriculture, and sustainable forestry practices to reduce emissions and increase carbon storage.

Adaptation Strategies:

• Infrastructure Improvements: Build flood defenses, resilient infrastructure, and seawalls to protect coastal areas from rising sea levels.

• Water Management: Improve water usage efficiency in drought-prone regions and promote water conservation.

• Climate-Resilient Crops: Develop drought- and flood-resistant crop varieties to maintain food security under changing climatic conditions.

• Public Health Adaptation: Enhance healthcare systems to respond to the increased risk of heat-related illnesses, vector-borne diseases (e.g., malaria), and other climate-sensitive health issues.

International Agreements

The global response to climate change involves numerous international agreements and collaborations aimed at reducing emissions and mitigating climate change:

• The Kyoto Protocol (1997): The first legally binding international agreement to reduce GHG emissions, though it mainly required developed countries to take action.

• The Paris Agreement (2015): A landmark agreement aiming to limit global warming to well below 2°C above pre-industrial levels. Countries submit Nationally Determined Contributions (NDCs) to reduce emissions, with regular reviews and updates.

• COP Conferences: The Conference of the Parties (COP) is held annually under the United Nations Framework Convention on Climate Change (UNFCCC), where governments discuss and negotiate actions to address climate change.

Key Terms and Concepts

• Carbon Footprint: The total amount of greenhouse gases emitted into the atmosphere due to human activities, usually expressed in tons of CO2-equivalent.

• Carbon Sequestration: The process of capturing and storing carbon from the atmosphere, either through natural methods (forests, soil) or technological means (carbon capture and storage).

• Feedback Loops: These are processes that either amplify or dampen the effects of climate change. For example, the melting of polar ice reduces the Earth's reflectivity (albedo), causing more solar radiation to be absorbed, thus accelerating warming.

Climate change represents one of the most significant global challenges in history. Understanding the science behind the atmosphere, greenhouse gases, and climate models is essential for making informed decisions about how to mitigate and adapt to climate change. Governments, industries, and individuals all have roles to play in reducing emissions and preparing for the inevitable changes caused by a warming world. Education and awareness are key to fostering a more sustainable and climate-resilient future.

Chapter 7

Natural Resources

Types of Natural Resources:

Natural resources are materials or substances that occur naturally in the environment and can be used for economic gain or to meet human needs. They can be classified into different categories based on their availability, renewability, and origin. The two main types of natural resources are renewable resources and non-renewable resources, but further subdivisions provide a more nuanced understanding of resource management.

Renewable Resources

Renewable resources are natural resources that are replenished naturally over time, making them sustainable if managed properly. They are typically regenerated by environmental processes and can be used continuously without running out, as long as they are not overexploited.

Examples of Renewable Resources:

• Solar Energy: Energy from the sun is inexhaustible and can be harnessed using solar panels for electricity or heat.

• Wind Energy: Airflow can be converted into electricity using wind turbines, making wind a clean, renewable energy source.

• Hydropower: Water flows, especially from rivers and dams, can be used to generate electricity without depleting the resource itself.

• Geothermal Energy: The Earth's heat can be tapped into for power generation or heating, especially in volcanic regions.

• Biomass: Organic materials like wood, agricultural waste, and other plant matter can be used for fuel or energy. If the biomass is replanted or replenished, it remains renewable.

• Forests and Timber: Trees and plants, if sustainably harvested, can regenerate and provide a continuous supply of wood, oxygen, and other ecosystem services.

• Water: Although water is renewable, it can become scarce in certain regions due to overuse, pollution, or climate change. It is essential for life, agriculture, and industrial processes.

Challenges:

• Overconsumption can exceed the renewal rate, leading to resource depletion (e.g., overfishing, deforestation).

• Mismanagement, like over-irrigation or excessive groundwater extraction, can render renewable resources unsustainable.

Non-renewable Resources

Non-renewable resources are resources that exist in finite quantities or are replenished at such a slow rate that they are considered finite on a human timescale. Once these resources are extracted and used, they cannot be replaced or take millions of years to regenerate.

Examples of Non-Renewable Resources:

• Fossil Fuels: These include coal, oil, and natural gas, formed over millions of years from the remains of ancient plants and animals. They are heavily used for energy production but are non-renewable and contribute significantly to environmental issues like climate change.

• Minerals: Metals like gold, silver, iron, copper, and aluminum are mined from the Earth. They are finite and take geological processes to form, making them non-renewable. Their extraction also causes environmental degradation.

• Nuclear Fuels: Uranium and thorium are non-renewable resources used in nuclear power plants to generate energy. While nuclear power produces fewer carbon emissions, the availability of these fuels is limited.

Challenges:

• Resource depletion leads to scarcity and higher prices as remaining reserves become harder to extract.

• Extraction processes, like mining and drilling, cause environmental damage, including habitat destruction, soil degradation, and pollution.

• Fossil fuels are major contributors to climate change, and their continued use is unsustainable in the long term.

Critical and Non-Critical Resources

Critical resources are those essential to modern economies but face potential supply risks due to their scarcity or geopolitical distribution.

• Critical Resources: Rare earth elements (REEs) like neodymium, used in electronics and renewable energy technologies, are critical because they are vital to technological advancement but are geographically concentrated in a few countries.

• Non-Critical Resources: Commonly available resources like construction materials (sand, gravel) are essential but generally abundant and face fewer supply risks.

Potentially Renewable Resources

Some resources fall into a middle ground and are termed "potentially renewable," meaning their sustainability depends on how they are managed.

Examples:

• Fisheries: Fish populations can replenish through natural reproduction, but overfishing can deplete them faster than they can recover.

• Soil: Healthy soil can regenerate with proper agricultural practices, but unsustainable farming can lead to erosion and desertification, making the soil non-renewable over time.

Flow and Stock Resources

Natural resources are also classified based on their flow and stock characteristics:

• Flow Resources: Resources like sunlight, wind, and water flow that are naturally abundant and must be used as they occur, as they cannot be stored for future use.

• Stock Resources: These include both renewable and non-renewable resources that exist in fixed quantities and are used over time, such as oil reserves or mineral deposits.

Sustainable Resource Management:

Sustainable resource management refers to the careful use and conservation of natural resources to meet current human needs while ensuring that these resources are available for future generations. The goal is to strike a balance between resource use, economic development, and environmental protection, reducing resource depletion and mitigating negative impacts on ecosystems.

Strategies for Sustainable Use of Resources

Different strategies can be implemented across various sectors to manage natural resources sustainably. These strategies aim to minimise waste, reduce environmental degradation, and encourage responsible consumption.

• Resource Efficiency: Improving the efficiency of resource use in production processes to extract more value with less input (e.g., using energy-efficient machinery, reducing water waste in agriculture).

• Circular Economy: A model that promotes the reuse, recycling, and repurposing of materials to minimize waste and reduce the demand for new raw materials (e.g., recycling metals, using organic waste for bioenergy).

• Renewable Energy Adoption: Shifting from non-renewable energy sources (like coal, oil, and gas) to renewable ones (like solar, wind, and hydroelectric power) to reduce greenhouse gas emissions and reliance on finite resources.

• Sustainable Agriculture: Implementing practices like crop rotation, organic farming, reduced pesticide use, and water conservation methods to maintain soil fertility and reduce environmental impacts.

• Integrated Water Resource Management: Efficiently managing water resources by balancing competing uses such as agriculture, industry, and urban needs, and ensuring water remains clean and accessible.

Concepts of Resource Substitution and Conservation

Resource substitution and conservation are key concepts that support sustainable resource use. These approaches focus on replacing or reducing the use of scarce or environmentally harmful resources and preserving them for future use.

Resource Substitution:

This involves replacing a resource that is scarce or environmentally damaging with one that is more sustainable or readily available.

Examples:

• Energy Substitution: Replacing fossil fuels with renewable energy sources like solar or wind energy to reduce carbon emissions.

• Material Substitution: Using alternative materials that are more sustainable, such as replacing plastic packaging with biodegradable materials like paper or using bamboo in place of hardwoods in construction.

Resource Conservation:

This refers to the protection, preservation, and careful management of natural resources to prevent their degradation or depletion.

Conservation Techniques:

• Reducing Consumption: Encouraging the efficient use of resources and reducing overall demand through lifestyle changes, policy measures, and technological advancements (e.g., reducing water usage, cutting down on energy consumption).

• Sustainable Forestry: Practicing selective logging, reforestation, and enforcing logging quotas to maintain forest ecosystems and prevent deforestation.

• Marine Conservation: Establishing fishing quotas, protected marine areas, and regulating fishing practices to prevent overfishing and maintain biodiversity in oceans.

Both substitution and conservation are crucial to slowing down the depletion of non-renewable resources and ensuring that renewable resources are used within their regeneration capacities.

Environmental Impact Assessments (EIAs)

An Environmental Impact Assessment (EIA) is a formal process used to predict the environmental consequences of proposed development projects or activities. It is a crucial tool for sustainable resource management, ensuring that potential environmental risks are considered before any significant changes to the environment occur.

Key Steps in EIAs:

1. Screening: Determining whether a project requires an EIA based on its scale, location, and potential impacts.

2. Scoping: Identifying the key environmental issues to be addressed, such as air and water pollution, habitat destruction, or resource depletion.

3. Impact Prediction: Assessing the likely environmental impacts of the project, including direct, indirect, short-term, and long-term effects on ecosystems, human health, and resource availability.

4. Mitigation: Proposing measures to avoid, minimize, or compensate for negative environmental impacts (e.g., restoring damaged habitats, using cleaner technologies).

5. Public Participation: Involving stakeholders, including local communities and environmental groups, in the decision-making process to ensure transparency and gather diverse perspectives.

6. Decision Making: Authorities use the EIA report to decide whether a project should proceed, be modified, or be canceled based on the potential environmental impacts.

7. Monitoring and Compliance: Once a project is approved, ongoing monitoring is required to ensure that mitigation measures are effective and that the environmental impacts remain within acceptable limits.

Importance of EIAs:

• Prevents Environmental Damage: By predicting and mitigating environmental risks before they occur, EIAs help protect ecosystems and communities from harmful effects.

• Promotes Sustainable Development: Ensures that economic growth is balanced with environmental protection, promoting long-term sustainability.

• Legal Compliance: Many countries require EIAs as part of their environmental regulations, ensuring that projects meet legal environmental standards.

Energy Resources:

Global Patterns of Energy Production and Consumption

It examines both geographical and socio-economic factors that influence energy use and production.

• Energy Production: The sources of energy (fossil fuels, nuclear, renewables) vary by region based on resource availability. For example, the Middle East is a major producer of oil, while countries like China rely heavily on coal for energy production.

• Energy Consumption: Wealthier, industrialized nations typically have higher energy consumption per capita due to higher living standards and greater industrial activity, while developing nations may have lower energy consumption but increasing demand due to population growth and industrialization.

Case Study Example:

• The United States: A high-energy consumer, with significant reliance on fossil fuels, but a growing use of renewable energy like solar and wind.

• Sub-Saharan Africa: Lower energy consumption overall, but facing energy poverty and increasing demand as economies grow and populations expand.

Case Studies on Energy Security and Energy Conflicts

Energy security refers to a country’s ability to secure an adequate and reliable supply of energy at affordable prices. Energy conflicts arise when access to energy resources becomes contested, often due to geopolitical tensions or competition over scarce resources.

• Energy Security: Countries may struggle with energy security if they rely heavily on imported energy, especially from politically unstable regions (e.g., Europe’s dependence on Russian gas).

• Energy Conflicts: Competition over energy resources can lead to conflicts, especially in areas rich in oil or gas (e.g., disputes in the South China Sea over oil reserves, Russia-Ukraine conflicts over gas pipelines).

Case Study Example:

• Russia and Europe: The dependence of European countries on Russian natural gas has led to energy security concerns, especially following political tensions and the Russia-Ukraine conflict, which has affected gas supplies.

• Middle East Oil Conflicts: Many conflicts in the Middle East, such as the Gulf Wars, have involved disputes over oil resources and control of energy supplies.

Renewable vs. Non-Renewable Energy Sources

The environmental and economic impacts of both types of energy are crucial to understand.

• Renewable Energy Sources: These include solar, wind, geothermal, and hydropower. They are generally considered cleaner and more sustainable, but can be expensive to develop initially and dependent on geographic and climatic conditions.

• Non-Renewable Energy Sources: Fossil fuels (coal, oil, natural gas) and nuclear energy. These are currently more widely used due to existing infrastructure, but they contribute heavily to pollution and climate change.

Case Study Example:

• Germany’s Energiewende: Germany has made a significant push toward renewable energy, particularly wind and solar, as part of its energy transition policy (Energiewende). It aims to reduce dependence on fossil fuels and phase out nuclear energy.

Saudi Arabia’s Oil Economy: Saudi Arabia’s economy heavily relies on oil production, a non-renewable resource. The country is now exploring ways to diversify its economy and invest in renewable energy projects.

Impacts of Energy Use on the Environment (e.g., air pollution, climate change)

Different energy sources have different impacts on the environment, and understanding these is critical for managing resources sustainably.

• Fossil Fuels: Burning coal, oil, and natural gas releases greenhouse gases (GHGs) like CO₂, contributing to global warming and climate change. It also causes air pollution, leading to smog and health issues.

• Renewables: While renewable energy sources are generally much cleaner, they have their own environmental impacts. For example, hydropower can disrupt ecosystems, and wind turbines may affect bird populations.

• Nuclear Energy: Produces low GHG emissions but poses risks related to radioactive waste and potential nuclear accidents (e.g., Chernobyl, Fukushima).

Case Study Example:

• Air Pollution in China: China’s heavy reliance on coal for energy has resulted in significant air pollution problems in major cities like Beijing. The country is now focusing on renewable energy to reduce its environmental impact.

• Climate Change: Global reliance on fossil fuels is a major contributor to climate change, leading to rising temperatures, sea level rise, and more frequent extreme weather events.

Water Resources:

Global Distribution and Accessibility of Freshwater

Freshwater is unevenly distributed across the globe, both in terms of availability and access. While water is abundant in some areas, others face significant scarcity due to physical and economic factors.

• Distribution: Only 2.5% of Earth's water is freshwater, and much of it is locked in glaciers and ice caps, leaving less than 1% accessible for human use in lakes, rivers, and groundwater.

• Physical Water Scarcity: Occurs in regions where water is naturally scarce due to climatic factors, such as arid and semi-arid regions (e.g., the Middle East, parts of Africa).

• Economic Water Scarcity: Exists in areas that have enough water but lack the infrastructure to access or distribute it (e.g., parts of sub-Saharan Africa). This limits people's access to clean and safe drinking water.

• Unequal Access: Even in water-rich countries, access may be unequal due to political, social, or economic barriers. Urban areas often have better access than rural regions.

Case Study Example:

• Sub-Saharan Africa: Many countries face economic water scarcity despite having potential water sources in rivers and lakes. Lack of infrastructure prevents access to clean water for much of the population.

• Canada: One of the most water-abundant countries in the world, with significant freshwater resources from rivers, lakes, and glaciers.

Water Scarcity and Conflicts

Water scarcity refers to the situation where water availability is insufficient to meet the demands of the population. This scarcity can lead to tensions and conflicts, both within and between countries, especially where water resources are shared.

• Types of Scarcity: Physical scarcity occurs when natural water supplies are limited, while economic scarcity arises due to poor infrastructure or governance.

• Water Conflicts: Disputes often arise in regions where multiple countries or regions share water bodies, such as rivers and lakes. Competing demands for water resources for agriculture, industry, and domestic use can escalate tensions.

• Transboundary Water Conflicts: When rivers cross borders (e.g., Nile River, Mekong River), upstream activities like dam construction or over-extraction can negatively impact downstream countries, leading to conflicts.

• Climate Change: Increasing temperatures and changing precipitation patterns due to climate change exacerbate water scarcity in already vulnerable regions, potentially leading to migration and conflicts over water resources.

Case Study Example:

• Nile River Basin: The Nile flows through multiple countries, including Egypt and Ethiopia. Ethiopia’s construction of the Grand Ethiopian Renaissance Dam (GERD) has raised tensions with downstream countries, particularly Egypt, which relies heavily on the Nile for its freshwater needs.

• Middle East Water Conflicts: Countries like Israel, Jordan, and Palestine face chronic water scarcity, leading to disputes over shared water sources such as the Jordan River.

Management of Water Resources

Proper management of water resources is crucial to addressing water scarcity, ensuring that freshwater is used efficiently and sustainably. Different techniques and technologies are employed depending on the needs and geography of the region.

• Desalination: A process that removes salt from seawater to produce freshwater, mainly used in arid regions like the Middle East. While effective, it is energy-intensive and expensive, and has environmental impacts such as brine disposal.

• Irrigation: A key component of agriculture, especially in dry areas. Modern irrigation techniques, such as drip irrigation, are designed to minimize water waste and improve efficiency compared to traditional methods.

• Water Conservation: Efforts to reduce water use, especially in agriculture, industry, and urban areas, through technologies like water-efficient fixtures, recycling, and rainwater harvesting.

• Integrated Water Resource Management (IWRM): A holistic approach to managing water resources that balances the needs of all sectors (agriculture, industry, domestic use) and considers the environmental and social impacts of water use.

Case Study Example:

• Desalination in Saudi Arabia: As one of the world’s most water-scarce countries, Saudi Arabia relies heavily on desalination to provide drinking water. This technology supplies a significant portion of the country's water, but it has high energy costs.

Irrigation in India: India is highly dependent on irrigation for agriculture, especially in water-stressed regions. The country has implemented more efficient irrigation systems, like drip and sprinkler irrigation, to combat water scarcity.

Virtual Water and Water Footprint Concepts

These concepts highlight the hidden water embedded in the production of goods and services, making people more aware of their indirect water consumption.

• Virtual Water: Refers to the total volume of water used in the production and trade of goods and services. For example, producing 1 kilogram of beef requires about 15,000 liters of water, while producing a cup of coffee requires about 140 liters of water.

• Water Footprint: The total amount of water used by an individual, business, or country. This includes both direct water use (e.g., drinking, washing) and indirect water use (e.g., water embedded in food and products).

• Global Trade and Virtual Water: Countries that export water-intensive products (e.g., food, textiles) are effectively exporting virtual water. Water-scarce countries can reduce their water footprint by importing such products instead of producing them domestically.

• Sustainable Water Use: Understanding virtual water and water footprints helps raise awareness about the global interconnectedness of water use and encourages consumers and governments to reduce water waste.

Case Study Example:

• Water Footprint of the United States: The U.S. has a large water footprint, partly due to high levels of meat consumption and water-intensive agricultural practices.

• Virtual Water Trade: Countries like Japan and the Middle East, which are water-scarce, import significant amounts of virtual water by importing food, thereby conserving their own freshwater resources.

Mineral Resources:

Global Patterns of Mineral Extraction

Mineral extraction refers to the process of mining minerals from the Earth. These minerals include metals (e.g., iron, copper, gold), non-metallic minerals (e.g., limestone, salt), and energy minerals (e.g., coal, uranium). The distribution of mineral resources is uneven across the globe, and extraction is concentrated in specific regions where geological conditions are favorable.

• Major Mining Regions:

  • Africa: Rich in a variety of minerals such as gold, diamonds, and rare earth elements. South Africa, for instance, is known for its platinum and gold production.

  • Australia: A significant producer of iron ore, coal, and bauxite.

  • South America: Major mining regions include Brazil (iron ore), Chile (copper), and Peru (silver, copper).

  • North America: The United States and Canada are key producers of coal, copper, and gold.

  • Russia: One of the world's leading producers of diamonds, gold, and nickel.

• Economic Importance: Many developing nations depend on mineral exports for income, while developed nations rely on minerals for industrial production. The global demand for minerals is increasing, driven by industrialization, urbanization, and technological advances.

Case Study Example:

• Chile: The world's largest copper producer, accounting for a significant portion of global supply. Copper mining is central to the Chilean economy, contributing substantially to its GDP.

• Australia: A major global player in mining, particularly in iron ore, coal, and gold, contributing significantly to its export revenues.

Environmental and Social Impacts of Mining

Mining activities, while economically important, can have profound environmental and social impacts, especially in regions where regulations may be weak or mining is conducted irresponsibly.

• Environmental Impacts:

  • Deforestation and Habitat Destruction: Mining often requires clearing large areas of land, leading to the destruction of ecosystems and loss of biodiversity.

  • Soil and Water Pollution: The release of toxic chemicals, such as mercury and cyanide (used in gold mining), and the runoff from tailings (waste products) can contaminate soil and water bodies, leading to long-term environmental damage.

  • Air Pollution: Dust and emissions from mining operations and associated processing activities can lead to air quality degradation, affecting both local communities and wildlife.

  • Energy-Intensive: Mining often requires large amounts of energy, typically from fossil fuels, contributing to greenhouse gas emissions and climate change.

• Social Impacts:

  • Displacement of Communities: In some regions, mining projects force local communities to relocate, disrupting livelihoods and leading to conflicts.

  • Health Risks: Communities living near mines are often exposed to air and water pollution, which can lead to health problems such as respiratory issues and waterborne diseases.

  • Labor Exploitation: In some countries, mining is associated with poor labor conditions, including low wages, dangerous working environments, and, in extreme cases, child labor.

Case Study Example:

• Amazon Rainforest, Brazil: Illegal gold mining in the Amazon has led to severe deforestation, mercury pollution in rivers, and conflicts with indigenous communities. The environmental degradation is impacting biodiversity, and mercury contamination poses health risks to local populations.

• South Africa: The mining of gold and platinum has caused environmental degradation and serious social issues, including land conflicts, worker exploitation, and the health impacts of mining dust.

Strategies for Reducing Reliance on Finite Mineral Resources

As mineral resources are finite and non-renewable, there are growing concerns about their depletion. To reduce reliance on mining and conserve finite mineral resources, various strategies can be employed.

• Recycling and Reuse: Recycling metals and minerals from used products (e.g., electronics, vehicles) reduces the need for new extraction. For example, metals like aluminum, copper, and gold can be recovered from discarded electronics (e-waste) and reused in new products.

• Sustainable Mining Practices: Encouraging more sustainable methods of extraction that minimize environmental damage. This can include using less water, reducing emissions, and rehabilitating mined areas.

• Substitution: Replacing scarce minerals with more abundant alternatives. For example, using aluminum instead of copper in some electrical applications or developing synthetic alternatives to rare earth minerals.

• Urban Mining: Extracting valuable minerals from waste products in urban environments, such as scrap metal from old buildings or precious metals from electronic waste.

• Regulation and International Agreements: Governments and international organizations can implement stricter regulations on mining operations to ensure environmental protection and ethical practices. Certification schemes, like the Fairtrade Gold initiative, aim to ensure mining is done responsibly and without harm to workers or the environment.

Case Study Example:

• E-waste Recycling: Countries like Japan and Switzerland have advanced recycling programs to extract precious metals from electronic waste, reducing the need for new mining operations.

• Substitution in Battery Production: As the demand for electric vehicles rises, companies are researching alternatives to lithium and cobalt (used in batteries) to reduce the environmental and ethical issues associated with mining these materials.

Chapter 8

Human Populations and Urban Systems (IB)

Basic Vocab and Information For Human Population Dynamics

Vocab

• Demographics: study of dynamics of population change

• Crude Birth Rate: The number of live births per 1,000 people per year.

• Crude Death Rate: The number of deaths per 1,000 people per year.

• Natural Increase Rate: The rate of population growth, calculated as ((CBR-CDR)/10)

• Doubling Time: The number of years it takes for a population to double in size, calculated using the rule of 70 (70 / NIR).

• Total Fertility Rate: The average number of children a woman is expected to have during her lifetime.

• The average number of children a woman is expected to have during her lifetime.

More Economically Developed Countries (MEDCs)

• Examples: Europe, North America, South Africa, Israel, Japan

Characteristics:

• High GDP per capita

• Higher standards of living

• Access to better healthcare and education

• Low population growth rates due to low CBR and CDR

• High ecological footprints

Less Economically Developed Countries (LEDCs)

• Examples: Sub-Saharan Africa, many parts of Asia, South America
  Characteristics:

  • Lower GDP per capita

  • Higher levels of poverty

  • Higher population growth rates due to higher CBR and declining CDR

  • Lower ecological footprints

Human Adaptability and Carrying Capacity

• Flexibility:

  • Importing food and resources

  • Reducing family size through family planning

  • Adaptation and mitigation strategies such as education, healthcare improvement, and income enhancement

  • Changes in dietary choices

Reasons for large families

• High infant mortality rate

• Security in old age

• Economic assets: agriculture

• Status of women

• Contraceptives

Demographic Transition Model

Stages

1. High Stationary: High birth and death rates due to limited birth control, high infant mortality, and little medical advancement.

2. Early Expanding: Death rates drop due to improved healthcare and sanitation, birth rates remain high, leading to rapid population growth.

3. Late Expanding: Birth rates start to decline due to increased use of contraceptives, better education, and women's empowerment.

4. Low Stationary: Both birth and death rates are low, stabilizing the population.

5. Declining: Birth rates fall below death rates, leading to an aging population and potential population decline.

Limitations

• Initial model didn’t have 5th stage - only recently countries have become part of this(Germany, Sweden)

• Fall in death rate hasn’t been as steep

• Death from AIDS-related diseases can affect this

• Assumptions about contraceptive availability and societal changes that may not hold true everywhere.

• Assumes increasing education and literacy for women (not always the case)

Theories of Population Growth

Malthusian Theory

• Food supply was a limit to population growth.

• Population can never increase beyond food supplies necessary to support it.

• Too simplistic.

• Ignore reality (only the poor go hungry).

• Did not account for technological advancements or distribution inequalities.

Boserup Theory

• Technological advancements can increase food production.

• Population growth leads to development

• Assumes closed communities, not accounting for migration and external factors.

• Migration happens in overpopulated areas

• Overpopulation can lead to bad farming

Basic Vocab and Information for Resource Use in Society

Vocabulary

• Renewable Natural Capital: Resources that can regenerate or be replaced (e.g., forests, solar energy).

• Non-Renewable Natural Capital: Resources that are finite and cannot be replaced on a human timescale (e.g., fossil fuels, minerals).

• Natural Capital: Resources that provide economic, ecological, and intrinsic value to humans.

• Capital includes:

  • Natural sources with value (trees, water)

  • Natural sources that provides services (flood protection)

  • Processes (water cycle)

Renewable Capital

• Living species and ecosystems using solar energy and photosynthesis.

• Groundwater, if managed sustainably.

• The ozone layer.

Non-Renewable Natural Capital

• Fossil fuels, minerals

• Finite amounts: not renewed/replaced after they’ve been used/depleted

• Alternatives need to be found

Arctic

• Mineral riches surrounding Arctic Ocean (hydrocarbons)

• Climate change causing it to warm up (more ice-free days)

• Canada, Denmark, Iceland, Norway, Russia, US have Arctic Ocean coastlines

• They are jostling for ownership of the region's frozen seas.

Antarctic

• 98% covered in ice and snow

• Humans exploit it through tourism, fishing and whaling

• Nobody owns it but seven have staked territorial claims via “The Antarctic Treaty”

Changing value of natural capital

• Cork forests

  • Previously used to seal wine bottles

  • Being replaced by screw top bottles and plastic corks

  • Forests losing value due to not being used as natural capital to humans

  • Not a good thing because they are not biodegradable

• Lithium

  • More than half of lithium reserves are under a desert salt plain in Bolivia

  • Lithium production not enough to power electric cars if they were to replace cars with petrol engines

Valuing Natural Capital

• Use Valuation - use natural capital we can put prices on

  • Economic price of marketable goods

  • Recreational functions (tourism)

• Non-use Valuation - natural capital that it is impossible to put a price on

  • If it has intrinsic value (right to exist)

  • If it has future uses we aren’t aware of (Science, Medicine)

  • If it has existential value (Amazon rainforest)

Solid Domestic Waste

• Trash, garbage, rubbish

• Something is waste when there is no value for the producer

Linear model of producing: take, make, dump

The circular economy aims to:

• Be restorative of the environment

• Use renewable energy source

• Eliminate or reduce toxic wastes

• Eradicate waste through careful design

Strategies to minimize waste

• Reduce

  • Change shopping habits, buy things that will last

  • Buy energy efficient, recyclable goods

• Reuse

  • Compost food waste

  • Use old clothes as cleaning rags

  • Read E Books

• Recycle

Strategies for waste disposal

• Landfills

  • Cheap initial cost

  • Away from highly populated area

  • Lined with special plastic liners to prevent liquid waste from leaving the area+

  • Methane used to generate electricity

  • Issues with leaking gases

  • Contaminate groundwater & crops

  • Cause health problems

• Incinerators

  • Burning waste causes air pollution (release harmful gases)

  • Expensive

  • Need a lot of waste to use this (does not discourage waste reduction)

  • Generates steam and powers heat powered buildings nearby

  • Ash can be used in road building

  • Space taken up is smaller than landfills

• Anaerobic digestion: biodegradable matter broken down by microorganisms in theabsence of oxygen

  • Renewable

  • Methane used as fuel and waste used as fertilizer

  • HIgh set up cost

  • Feasible for large farms mainly

• Domestic Organic Waste: can be composted or put into anaerobic bio-digesters

  • Eco-friendly and methane produced can be used as fuel, improve soil health

  • Takes up space, only organic matter can be used, health and safety concerns (smell)

Human Systems and Resource Use

Carrying Capacity:

• The maximum population size an environment can sustainably support.

• Measurement challenges due to variable resource use, technology, and importation of resources.

Difficulties in measuring human carrying capacity

• Greater range of resources used

• Substitution of resources if others run out

• Resource use varies person to person

• Import resources from outside our immediate environment

• Developments in technology

• Importing resources —> increases carrying capacity for local population (no influence on globalcarrying capacity)

Ways to change human carrying capacity

• Ecocentric

  • Try to reduce their use of non-renewable resources

  • Use solar cells for electricity and rain water for water supply

• Technocentric

  • HCC can be expanded through technological innovation

  • Reuse, recycle and remanufacturing

Ecological footprint: area of land and water required to support a defined human population ata given standard of living

• The model estimates demands that human population place on the environment

• Vary country to country (due to lifestyle choices)

• 2012: EF of all people was equivalent to 1.5 Earths

Factors

• Area of land needed to absorb wastes (water, sewage, CO2)

• Population size

• Cropland to grow food

• World carrying capacity does not change but local does.

Chapter 9

Environmental Law (IB)

Basics of Law

• Laws are fundamental rules that regulate and govern human behaviour within a society

  • For example, traffic laws regulate how drivers should behave on the roads to ensure safety and order

• Laws are established and enforced by social or governmental authority to maintain order and protect rights

  • For example, laws prohibiting theft ensure the protection of individuals' property rights and contribute to the overall safety and security of the community

  • Law enforcement agencies, such as the police, are authorised by the government to enforce these laws, investigating theft cases and apprehending offenders to uphold the rule of law and safeguard citizens' rights

Purpose and function of laws

• Laws serve multiple purposes, including governing human conduct, resolving conflicts, and promoting justice

  • They provide a framework for social order, ensuring stability and predictability in society

  • Laws also act as a deterrent against undesirable behaviours by imposing penalties for violations (i.e. when people break the law)

Sources of law

• Laws can originate from various sources, including legislation, common law, administrative regulations, and international treaties

  • Legislation refers to laws enacted by a legislative body, such as a parliament or congress

  • Common law derives from judicial decisions and precedent established through court rulings

  • Administrative regulations are rules and regulations created by administrative agencies to implement laws

    • For example, the Environmental Protection Agency (EPA) in the United States is an administrative agency tasked with implementing and enforcing environmental laws and regulations

  • International treaties are agreements between sovereign states governing interactions between nations

    • For example, the Paris Agreement was an international treaty signed in 2015 that aims to combat climate change by limiting global warming to well below 2 °C above pre-industrial levels

Enforcement of laws

• Law enforcement agencies are responsible for upholding and enforcing laws within a jurisdiction

  • Enforcement mechanisms may include police, courts, and correctional systems (e.g. prisons or jails)

  • Penalties for violating laws can range from fines and community service to imprisonment, depending on the severity of the offence

Consequences of absence of law

• Without laws, societies would descend into chaos and anarchy, with individuals free to act as they please without consequences

  • Lack of legal framework undermines social order, leading to conflict, violence, and oppression

  • The absence of law threatens people's fundamental rights and freedoms, leaving individuals vulnerable to exploitation and injustice

  • An example of this can be seen in failed states like Somalia, where the absence of a functioning legal system has led to widespread lawlessness and violence

Rule of law

• The rule of law is the principle that asserts that everyone is subject to the law, including government officials

• Key concepts underpinning the rule of law include:

  • Equality: All individuals are equal before the law, regardless of status, wealth, or power

  • Fairness: Legal processes and decisions should be impartial and unbiased, ensuring fair treatment for all

  • Liberty: Laws should protect individual liberties and freedoms, limiting government intrusion into personal affairs

  • Justice: The legal system should strive to achieve justice by providing remedies for wrongs and ensuring accountability for violations

Overview of Environmental Law

Definition of environmental law

• Environmental law includes the legal principles, regulations, and treaties governing the interaction between human activity and the environment

  • It focuses on regulating human behaviour to minimise negative impacts on natural resources and ecosystems, promoting sustainability and environmental protection

  • It provides a framework for balancing economic development with environmental preservation, safeguarding the well-being of current and future generations

Scope of environmental law

• Environmental law covers various aspects of human-environment interactions, including (but not limited to) the following:

Main Aspects Covered by Environmental Law

• Understanding the fundamental aspects of environmental law is essential for addressing environmental challenges and achieving sustainable development

Chapter 10

Environmental and Ecological Economics (IB)

Basics of Economics

• Economics is the study of how people make choices about what to produce, how to distribute goods and services and how to use them

  • It examines how individuals and societies allocate scarce natural resources to satisfy their wants and needs

    • This is sometimes referred to as the economic problem

  • Economics explores both individual decision-making and collective behaviour in markets and economies

How these three questions are answered determines the economic system of a country

Supply and demand

• Supply refers to the quantity of a good or service that producers are willing and able to offer for sale at different prices

• Demand refers to the quantity of a good or service that consumers are willing and able to buy at different prices.

• The interaction of supply and demand determines the equilibrium price and quantity in a market

  • For example, if the price of smartphones decreases, the demand for smartphones may increase because more people can afford to buy them

Market interaction

• Markets are any location or platform (both physical and virtual, i.e. online) where buyers and sellers come together to exchange goods and services

• Market interaction involves the exchange of goods and services based on the forces of supply and demand

  • For example, in a farmer's market, farmers supply fresh produce, and consumers demand fruits and vegetables

  • The prices are determined by the balance between what farmers are willing to sell and what consumers are willing to pay

Examples of Markets

Introduction to Environmental Economics

• Environmental economics is a branch of economics that applies economic principles to environmental issues and the management of natural resources

  • It aims to understand how human activities impact the environment and how economic policies can be designed to achieve sustainable outcomes

• For example, consider the market for renewable energy:

  • As the demand for clean energy sources increases due to concerns about climate change, environmental economics helps to analyse which incentives and policies are needed to promote the development and adoption of renewable technologies

Technocentric vs. ecocentrics

• Technocentrics believe that advancements in science and technology can solve environmental problems within the existing economic framework

  • They emphasize the role of innovation in developing modern technologies to address environmental challenges (and therefore reduce their economic impacts)

  • For example, technocentrics may argue that investments in carbon capture and storage technologies can help mitigate greenhouse gas emissions from industries like power generation and manufacturing

• On the other hand, ecocentrics support a more holistic approach that prioritizes fundamental changes in human behavior towards sustainable living

  • They do not believe that environmental problems can be solved within the existing economic framework

  • They emphasis the importance of living in harmony with nature rather than relying solely on technological solutions

  • This may require challenging or transforming existing economic systems and practices

  • An example of this perspective is the promotion of sustainable lifestyles, such as minimalism and zero-waste living, which aim to reduce consumption and minimize environmental impact

There is a broad range of environmental value systems held by people and groups around the world – on a basic level these EVSs usually fall into one of three main categories

Perspectives on solutions

• The existing economic system often relies on the belief that scientific and technological advancements will be sufficient to address environmental challenges

  • This perspective is demonstrated by policies and initiatives that focus on developing modern technologies to mitigate environmental impacts

  • For example, government subsidies for electric vehicles and renewable energy projects aim to incentivize technological innovation and reduce dependence on fossil fuels

• In contrast, supporters of environmental economics argue for a shift towards sustainable and responsible human behavior as a solution to environmental issues

  • This approach is demonstrated by policies and initiatives that prioritize environmental protection and social well-being over economic growth

  • An example of this approach is the use of environmental regulations that restrict harmful activities and promote sustainable resource management, e.g. regulations on emissions standards for vehicles, which aim to reduce air pollution and improve public health

Chapter 11

Environmental Ethics

HL.c.1 - Ethics is the branch of philosophy that focuses on moral principles and what behaviors are right and wrong

Importance of Ethics

• It helps us determine moral principles that will guide how humans act and justify their actions in different situations

  • It helps us ensure that our actions align with our values

Different Approaches to Ethics

• Deontological Ethics (Duty-Based Ethics):

  • This framework states that an action is good or bad based on rules and principles, regardless of the action’s consequences

  • Consequentialism (Outcome-Based Ethics):

    • This framework suggests that an action is good or bad based on what the consequences of that specific action are

  • Virtue ethics:

    • This framework says that good actions are carried out by people who possess good moral traits, such as loyalty, courage, kindness, and wisdom

    • A broad term that focuses on people, not actions

How Ethics are Influenced by Culture and Traditions:

• Religious influences

  • Collectivism vs individualism

    • Collectivist societies: value the needs of a group/community

    • Individualist societies: value individual freedoms and rights

  • Environmental ethics

    • Some societies believe humans should respect the environment and protect the natural world

  • Moral relativism

    • What is considered ethical varies across different societies

  • Globalization and ethical conflicts

How Ethics Influences Everyday Life

• Daily decisions

  • Small and big choices in everyday life are influenced by an individual’s morals

  • Societal norms

    • What a society collectively views as right or wrong

  • Behaviors

  • Societal development

    • Ethical principles shape how society develops in many aspects (ex. Economic, environmental, social)

  • Global challenges

    • Global politics and challenges are also shaped by ethics

HL.c.2 - Environmental ethics is a branch of ethical philosophy that addresses environmental issues

Environmental Ethics: A branch of philosophy that focuses on the relationship humans have with the living and nonliving components of the natural world

• Began in the 1960s and 1970s

  • Emerged after growing public concern about pollution, species extinction, and resource depletion

  • Went against traditional ethics, which focused more on human-to-human actions, and expanded to develop ethical principles that included non-human interactions

  • Challenged the idea that nature’s value is only determined by how useful it is to humans

  • Proposed that humanity's relationship with the environment should be seen as a moral concern

Important Concepts and Theories:

• Intrinsic vs. instrumental value

  • The elements of nature have intrinsic value that does not depend on it’s utility to humans

Ecocentrism

• Human-centered ethical considerations should be replaced by a nature-centered approach

The Land Ethic

• Theory by Aldo Leopold that includes nature as part of a community

HL.c.3 - A variety of ethical frameworks and conflicting ethical values emerge from differing fundamental beliefs concerning the relationship between humans and nature

Ecocentric Ethics:

• Belief that all components of nature are considered equal to humans

  • Key principles:

    • All parts of nature have inherent value

    • All parts of nature have rights

    • All decisions made by humans should either not harm or benefit the environment

Technocentric Ethics:

• Belief that nature’s purpose is to serve human needs

  • The main goal is to maximize the amount of people who can benefit from the resources

  • Key Principles

    • Nature’s worth is determined by how useful it is to people

    • Ethical choices should focus on helping the most amount of people

    • Decisions, often at the expense of the environment, should be evaluated based on how much they benefit humans

HL.c.4 - Instrumental value is the usefulness an entity has for humans

Instrumental Values

• A value that helps people achieve specific end goals

  • In environmental ethics, it focuses on how useful something in nature is to human needs/desires

Impact of Instrumental Value on Human’s Relationship with Nature

• Resource Conservation

  • The preservation of nature can be justified by the desire to prevent negative effects on human health (such as floods, and air pollution), rather than preserving nature purely for its intrinsic value

  • Different Views on the Exploitation of Nature

    • Anthropocentric views: This view recognizes that the exploitation of nature exists, but advocates for sustainable practices solely because it threatens human survival

    • Technocentric views: This view proposes that technology can substitute everything provided by nature

HL.c.5 - Intrinsic value is the value one may attach to something simply for what it is

Intrinsic Value

• Refers to the inherent worth something has, which is completely independent of how beneficial it might be

  • Very important concept in environmental ethics

    • Promotes biodiversity

    • Encourages restoration efforts

Challenges in Applying Intrinsic Value

• Measuring: Intrinsic value is subjective, it cannot be quantified or economically assessed

  • Implementation: In systems driven by economic consideration, it’s difficult to integrate intrinsic values into policy

HL.c.6 - The concepts of instrumental and intrinsic value are not exclusive

Balance between Intrinsic and Instrumental Values

• Policy Formation

  • Both values are considered when a government is forming a policy that addresses environmental concerns

  • Conservation Efforts

    • Sometimes the instrumental value of an element of nature leads to increased conservation efforts, such as preserving a forest because it is a tourist attraction, so both values are considered

HL.c.7 - An entity has “moral standing” if it is to be morally considered about how we ought to act towards it

Moral Standing

• A belief that determines if acting morally towards an entity will make a difference

  • An aspect of moral standing is whether or not future generations should be taken into consideration when making ethical decisions

  • Biocentric Environmental Ethics:

    • Ethics that argues all living creatures have direct moral standing, and there is no real reason to act morally towards some species, but not others

Moral Standing of Living vs. Nonliving Entities

• Ecocentric

  • This viewpoint argues that nonliving entities (such as rivers, landscapes, and more) are essential parts of ecosystems and should be given moral standing

  • Anthropogenic and Technocentric

    • This viewpoint argues that unless a nonliving entity directly benefits humans, it does not have moral standing

Moral Standing of Different Living Organisms

• Sentient Animals

  • Some argue that animals that can feel pain or pleasure have moral standing

  • Microorganisms

    • Some ecocentric views also include the belief that microorganisms should have moral standing

HL.c.8 - There are three major approaches to traditional ethics: virtue ethics, consequentialist (for example, utilitarian) ethics, and rights-based (deontological) ethics

Application of the 3 types of Ethical Approaches

• Virtue Ethics

  • Applied when an individual’s behavior is a consequence of the individual being virtuous

  • Consequentialist Ethics

    • Applied when the behavior/action will result in the best possible consequences

  • Rights-based Ethics

    • Applied when the action taken respect and upholds the pre-existing rights of an individual or entity

HL.c.9 - Virtue ethics focuses on the character of the person doing the action. It assumes that good people will do good actions and bad people will do bad actions

Virtue Ethics in the Context of Environmental Ethics

• Respecting the natural world by acknowledging its intrinsic value

  • Caring about the impact humanity’s actions have on the environment

  • Recognizing the duty humanity has to take care of the natural world and taking steps to reduce the negative impact humans have on it

HL.c.10 - Consequentialist ethics is the view that the consequences of an action determine the morality of the action

Consequentialist Ethics in the Context of Environmental Ethics

• The goal is to make choices that will result in the greatest amount of benefit for the most people

  • Environmental policies are passed that will result in overall better health and a more stable climate

  • The sustainable management of resources results in the quality and quantity of the resources being better for future generations

HL.c.11 - Rights-based ethical systems focus on the actions and whether they conflict with the rights of others. There is debate about what these rights might be

Rights-based Ethics in the Context of Environmental Ethics

• Aligns with the concept of intrinsic value

  • The rights of animals are protected because they are considered to have intrinsic value and violating their inherent rights is unethical

  • Environmental conservation is prioritized because actions that degrade these ecosystems/natural features are considered unethical

  • Many Indigenous communities have traditions of recognizing the intrinsic value of nature for a very long time

HL.c.12 - Some people hold the view that whatever is natural is correct or good. This position is contentious and is described as the “appeal to nature” fallacy

“Appeal to nature” Fallacy

• Prominent discussion in diet choices, medical treatments, and environmental conservation

  • An argument that something is ethical simply because it is natural, which suggests that natural things are morally superior to unnatural ones

  • Overlooks the scientific validation of certain synthetic products, such as medicine, because it is unnatural

  • Often misleading argument, because it fails to consider the complexities of what is considered natural or not

    • Many synthetic substances originate from nature, so it's difficult to define when something is considered unnatural or not

    • Humans are a part of nature, so it’s unclear whether human intervention in nature is natural or unnatural

HL.c.13 - Environmental movements and social justice movements have developed from separate histories but are increasingly seeking common goals of equitable and just societies

• The exploitation of the environment that stems from the belief that humans are superior to nature parallels other forms of exploitation, such as sexism, racism, and economic inequality

Feedback loops and the connection between Economic, social and Environmental sustainability

• The connection between these three areas is crucial because the dynamics that result in social/economic inequalities also lead to environmental degradation, which will often harm the overall health of disadvantaged communities

  • Addressing issues in one of these areas will have an effect on the others, which can create a positive feedback loop and benefit many communities