Human Impacts on the Environment Vocabulary

Human Impacts on the Environment

Unit Overview

• Transportation networks illustrate human development's reach.

• The unit addresses human effects on the environment.

• Key questions:

  • How does population growth affect the environment?

  • How can we mitigate development's effects on biodiversity?

  • Why must environmental solutions meet societal needs?

Dams: Advantages and Disadvantages

• Dams provide energy and water but harm the environment.

• Assessment of dam impacts is essential.

• Humans should aim to reduce negative impacts and restore ecosystems.

• Project: Investigate the pros and cons of dams.

Pollution

• Millions of tons of trash enter oceans annually.

• Animals ingest plastic, mistaking it for food, leading to death.

• Animals get trapped in plastic waste.

• Plastic accumulation harms human and animal health.

• Solutions include:

  • Cleaning beaches.

  • Public education.

  • Recycling programs.

  • Developing technology to remove ocean plastic.

Human Impact Evident from Space

• Human activities significantly alter the geosphere, atmosphere, hydrosphere, and biosphere.

• Earth is approximately $4.5$ billion years old.

• Homo sapiens evolved around $200,000$ years ago.

• Increased population leads to greater resource dependence.

• Activities can be beneficial or harmful, impacting land, air, and water.

Population Growth and Natural Resources

• Population growth results from increased resource use and improvements in transportation, agriculture, health, and sanitation.

• Population pyramids analyze age group proportions in different countries, reflecting societal and environmental factors.

Carrying Capacity

• Earth's carrying capacity for humans is hard to predict.

• Carrying capacity: the maximum number of individuals an environment can support without significant negative impacts.

• Malthus (late 1700s) argued that population growth would outpace resource availability, leading to poverty and famine.

  • Malthusian theory: Population growth, if unchecked, will lead to resource depletion, poverty, and famine.

• Malthus's view: Poverty and famine are natural checks on population growth if it goes unchecked.

• Technological advancements have increased Earth’s carrying capacity.

• Industrial farming, sanitation improvements, and medical advances have extended human lifespans.

• The world population was over $7$ billion in $2015$ and is projected to reach $9.5$ billion by $2050$.

• Physician Ignaz Semmelweis's hand-washing concept in $1850$ revolutionized health and medicine, reducing disease spread.

• Ecological Footprint: Measures the amount of land and water required to support an individual or population, reflecting resource consumption and waste generation.

Natural Resources

• Natural resources: materials used by humans (water, petroleum, minerals, forests, animals).

• Classification: renewable or nonrenewable.

Renewable Resources

• Renewable resources: can be replaced at the consumption rate.

  • Wind energy: kinetic energy turns turbine blades to generate electricity.

  • Other forms: biomass, geothermal, hydroelectric, solar energy.

  • Solar energy: captured by solar cells to generate electricity.

• Potentially renewable resources (e.g., fresh water): renewable if not overused.

• Environmental impacts:

  • Burning biomass releases $CO_2$.

  • Dams alter river temperature and composition, affecting ecosystems.

Biomass and Human Health

• About one-third of the world's population burns biomass for heating and cooking.

• Indoor air pollution causes respiratory diseases.

• Cleaner, more efficient stoves are necessary.

Nonrenewable Resources

• Nonrenewable resources: used faster than they form (minerals, nuclear materials, fossil fuels).

  • Minerals: used in building materials, electronics, medical technologies.

  • Nuclear materials (uranium, plutonium): generate electricity through reactions.

  • Fossil fuels (coal, petroleum, natural gas): extracted via mining, hydraulic fracturing, drilling.

  • Hydraulic fracturing (fracking): injects water, chemicals, and sand into rock to release gases.

Per Capita Consumption

• Increased alongside population growth.

• Refers to the average amount of resources consumed per individual.

Extraction Methods

• Harm ecosystems and human health.

• Oil spills damage aquatic ecosystems and pollute drinking water.

• Coal miners can develop black lung disease.

• Fracking chemicals can contaminate water sources and harm humans.

Air Pollution

• Anything added to the environment with negative effects.

• Pollutants: chemicals, particulates, microorganisms.

• Common pollutants: fossil fuel emissions from vehicles, power plants, refineries, and industrial plants.

• Smog: caused by sunlight interacting with fossil fuel emissions, composed of particulates and ground-level ozone.

• Particulates: microscopic dust, metal, and unburned fuel that cause respiratory problems.

• Ground-level ozone ($O_3$): produced when nitrogen oxides react with oxygen in sunlight; harmful to ecosystems and human health; upper atmosphere ozone protects from UV rays.

Acid Rain

• Normal rain pH is about $5.6$ due to carbonic acid formation.

• Air pollutants (nitrogen and sulfur oxides) react with water to form sulfuric and nitric acids, lowering pH below $5.6$.

• Negative effects on soil:

  • Releases metal ions, preventing calcium absorption in plants.

  • Aluminum can kill fish and fish eggs.

  • Damages buildings, bridges, and statues.

Climate Change

• Earth's atmosphere acts like a greenhouse, trapping heat.

  • Greenhouse Effect: The trapping of the sun's warmth in a planet's lower atmosphere due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet's surface.

• Solar radiation enters, warms the surface, and is reradiated as infrared radiation.

• Greenhouse effect: keeps Earth at a habitable temperature.

• Increased greenhouse gases (carbon dioxide, methane) trap more energy.

• Global Warming Potential (GWP): measures how much heat a gas absorbs.

• Altered cycling of matter and energy among ecosystems.

• More intense hurricanes due to increased heat in oceans.

• Melting glaciers and ice caps raise sea levels.

• Ice cores: tubes of ice drilled to infer past $CO_2$ levels and temperatures (chemicals in snow, trapped air bubbles).

Greenhouse Gases

• Water vapor: variable concentration, GWP

Human Impacts on Water and Land

• Human activities alter land use and redirect water flow.

Impacts on Water

• Water usage: agriculture (67%), industry (19%), households (10%).

• Water pollution: caused by industry and population growth.

  • Point source pollution: from a single source (e.g., factory pipe).

  • Nonpoint source pollution: from many sources (e.g., fertilizer runoff).

Managing Water

• Wastewater treatment removes organic material and kills harmful bacteria.

• Dams:

  • Benefits: electricity generation, irrigation, flood control, drinking water.

  • Negatives: increased flood risk, silt deposition changes, altered water quality.

• Rainwater Catchment System: Collecting rainwater for household and commercial use to reduce reliance on freshwater sources.

Impacts on Land

• Increased land use for homes, agriculture, and resource extraction.

• Aluminum mining impacts organisms and ecosystems.

Soil Erosion

• Caused by clear-cutting forests, building structures, raising livestock, and growing crops.

• Reduces fertility and crop production.

• Can carry pathogens into water bodies.

• Artificial eutrophication: nutrient buildup from overfertilized soil.

• Soil compaction: reduces water absorption and plant root growth.

• Desertification: makes dry areas more desert-like due to drought, deforestation, and poor farming.

  • Deforestation: The clearing of forests for other land uses, leading to habitat loss and soil erosion.

• Soil and water engineering: conserve water and soil resources.

• Soil terracing and field residues reduce soil erosion and water loss.

Mining

• Removes rocks, soil, plants, and animals.

• Subsurface mining: extraction from below Earth's surface.

• Surface mining: removal of surface rocks and soil.

• Acid mine drainage: acidic water and metals contaminate water and corrode structures.

Desertification

• Areas at most risk are identified.

• Vulnerability factors are located.

Farming Practices

• Farming practices: can lead to soil erosion, artificial eutrophication and desertification

Human Impacts on Biodiversity

• Earth is currently experiencing a sixth mass extinction.

  • Extinction: The complete disappearance of a species from Earth.

• Habitat loss is the most common cause of species decline and extinction.

Clearing Land

• Clearing land in Borneo has led to significant habitat loss.

• The market for palm oil is growing and negative effects of palm plantations reach a critical level.

• Species such as the Bornean orangutan need rain forest habitat to survive and are therefore particularly sensitive to habitat loss.

Habitat Fragmentation

• Habitat fragmentation occurs when a barrier such as a road or cleared landscape divides a larger habitat into smaller sections, preventing individuals from accessing their full home ranges.

• Reduces suitable habitat and carrying capacity.

• Can lead to local extinction (extirpation).

• Increases edge effects (increased predation, unsuitable microclimates, pollution).

• Disrupts mating and breeding patterns.

Wildlife Corridors

• Connect isolated patches of habitat.

• Maintain gene flow and genetic diversity.

  • Riparian Corridors: Natural corridors along rivers or streams that provide habitat and connectivity for wildlife.

• Can be natural (riparian corridors) or artificial (highway underpasses).

• Nectar corridors support monarch butterfly migration.

Habitat Management

• Sustainable development meets current needs without causing permanent damage.

• Governments protect ecosystems by setting aside public lands.

• Historical milestones: Yosemite Grant of $1864$, Yellowstone National Park in $1872$, Antiquities Act of $1906$.

• National Park Service (NPS) established in $1916$.

• Endangered Species Act (ESA) of $1973$ protects species near extinction.

Introduced Species

• Native species live in their historical range.

• Introduced species are brought to new areas.

  • Native and Non-Native (Introduced) Species

• Invasive species cause economic or environmental harm or pose a threat to human health.

• Examples: zebra mussel and quagga mussel in the Great Lakes.

Invasive Species Management

• Methods: physical removal, chemical herbicides, burning, grazing, biological controls.

• Biological control agents: pests or predators from the invasive species’ home range.

• Economic impact: exceeds $\$100$ billion a year in the United States.

Overharvesting

• Occurs when organisms are removed faster than they can be replaced.

  • Overhunting: is an example of overharvesting, organisms are removed faster than they can be replaced.

• Example: American bison hunted nearly to extinction.

Overfishing

• If more individuals are removed than the population can produce.

• Aquatic species that have been overharvested: swordfish, Atlantic cod, and tuna.

Sustainable Fishing and Hunting Practices

• Regulations for catch size, season length, and equipment.

• Reduce bycatch.

• Wildlife managers regulate hunting seasons, animal age and sex, and equipment.

Rethinking the Value of Non-native Species

• Some non-native species provide important ecosystem services.

• Non-native plants often provide habitat for native species.

Engineering Solutions to Environmental Impacts

• Highways fragment habitats, making it difficult for animals to access their entire home range.

• Each situation has to be evaluated to determine the best wildlife crossing for the problem presented.

Converting Energy

• Petroleum products are mostly used as fuel for transportation.

• Natural gas is used to produce electric power and to heat buildings.

• Most coal is burned to produce electric power.

• Nuclear power plants use nuclear fission to produce electricity.

• Renewable energy is used for both electric power and transportation and does not emit greenhouse gases.

Converting Waste into Energy

• Household and commercially generated waste is often available and is not considered valuable.

• Engineers designed waste-to-energy incinerators as a solution to reduce the amount of trash entering landfills while capturing some of the energy stored in the waste.

  • Incineration: Burning waste to reduce volume and capture energy

Making Biofuel from Waste

• Some waste can be converted into biofuel, which keeps trash out of landfills and provides an alternative fuel source.

  • Biofuel: Fuel derived from organic matter, reducing landfill waste and providing an alternative energy source.

• Anaerobic digestion: microorganisms break down organic matter in the absence of oxygen, producing biogas.

Improving Solar Energy Efficiency

• Solar energy is a renewable alternative to more traditional forms of energy, such as electricity produced from coal.

• A common semiconductor in solar cells is silicon.

• Engineers have designed organic semiconductors to replace silicon in solar cells.

Habitat Management Resources

• Engineers are developing wood alternatives to take the place of traditional wood materials.

Making New Habitats

• Human populations have become increasingly urban over the last two centuries.

• Green roofing is an example of a solution that can lessen some problems of urbanization.

Lowering Carbon Dioxide Emission

• Regulating greenhouse gas emissions is becoming more common in many countries, but many scientists are worried that atmospheric carbon dioxide concentrations have already reached a tipping point.

• The process of removing $CO_2$ is known as negative emissions.

  • Negative Emissions: Technologies or practices that remove carbon dioxide from the atmosphere.

Decreasing Water Pollution

• Engineers are developing ways to solve the problems related to water access, water usage, and water pollution in order to ensure water is available in the future.

• Rainwater harvesting systems allow people to collect rainwater for household and commercial use instead of relying on freshwater