Environmental Science Study Notes

Environmental Science (CE 155) Lecture Notes by R. Buamah (PhD)

UNIT 1

  • Objectives / Goal

    • At the end of the course, students should understand the composition and mechanisms of operations of various elements in the environment.
    • Students should have knowledge about the sources and management of various kinds of pollution of the environment.

  • Learning Outcomes

    • Students should be able to appreciate the effect of domestic, industrial, vehicular, and other anthropogenic emissions and their causal effects on the environment.
    • Students should be able to identify, diagnose, and resolve problems associated with these activities.

Course Outline

  • Environmental Ethics and Sustainable Development (SDGs & Resources)
    • First & Second Week: Lecture Tour / Field Survey
  • Ecological Concepts and Interactions
    • Third Week: Lecture Group Work
  • Global Crisis
    • Fourth Week: Lecture
  • Soil Formation & Nutrient Cycles
    • Fifth & Sixth Week: Lecture
  • Environmental Impact Assessment (EIA), Public Health Hygiene & Public Awareness
    • Seventh to Tenth Week: Lecture & Presentation
  • Water Quality
    • Eleventh to Twelfth Week: Lecture & Presentation

Environmental Science

  • Definition: An interdisciplinary field that includes both scientific and social aspects of human impact on the world. It involves an understanding of the scientific principles and impacts, economic influences, and political actions.
    • Quote by John Muir: “Tug on anything at all and you will find it connected to everything else on the universe.”
    • Example: In the forest behind the college of Engineering laboratories, formerly used to harbor a number of trees, shrubs, biennials, and reptiles (e.g., snakes like pythons, cobras), as well as various species of birds and small mammals. Since development began, certain reptiles have either been killed or chased away, and farming activity has increased, leading to changes in wildlife populations in the area.

Environmental Ethics

  • Definition: The branch of philosophy that seeks to define what is right and wrong. Ethical dimensions are central to many issues discussed in this course.
    • Example 1: There is no law mandating assistance to an elderly neighbor, but helping them is ethically right.
    • Example 2: It is ethically right to properly dispose of litter like polythene bags after eating.
    • Goal of Environmental Ethics: To focus on the moral foundation of environmental responsibility.
Three Primary Theories on Moral Responsibility Regarding the Environment:
  1. Anthropocentrism
    • Human-centered ethics where moral responsibility is derived solely from human interests.
    • Flawed view as it neglects the importance of a hospitable Earth for future generations.
  2. Biocentrism
    • Life-centered ethics where all life forms have an inherent right to existence.
  3. Ecocentrism
    • Recognizes that the entire environment deserves direct moral consideration, not merely as a resource for human survival.

Sustainable Development (SD)

  • Definition: Meeting the needs of current generations without compromising the ability of future generations to meet their own needs.
  • Pillars of Sustainable Development:
    • Economic Development
    • Social Development
    • Environmental Protection
    • Consideration may also be given to cultural development.

Ecosystems

  • Roadmap for Sustainable Development: Established by the United Nations Conference on Environment and Development in 1992 in Rio de Janeiro, Brazil.
  • Follow-up Conference in 2002 (South Africa): Many observers questioned the lack of international progress in alleviating poverty and protecting the environment.

Environmental Science and Energy Principles

  • Information Provided: Details on environmental resources and how human activities affect their quality, composition, and constitution.
Resources
  • Definition: Any physical or virtual entity of limited availability or anything used to help one earn a living.
    • Broad Divisions:
    • Natural Resources
    • Human Resources
Natural Resources Classification
  1. Origin
    • Biotic: Living resources (e.g., forests, animals).
    • Abiotic: Non-living resources (e.g., land, water, air, minerals).
  2. Stage of Development
    • Potential Resources: Exists but not yet used.
    • Actual Resources: Surveyed and in use currently.
  3. Renewability
    • Renewable Resources: Inexhaustible (e.g., solar energy, fresh water).
    • Non-renewable Resources: Can be depleted (e.g., fossil fuels, metallic minerals).
Resource Exhaustion and Conservation
  • Renewable sources can become non-renewable if used at a faster rate than they can be replenished.
  • Examples: Certain animal and plant species have gone extinct due to overuse.
Mitigation Measures for Resource Management
  • Techniques:
    • Recycle
    • Reuse
    • Recovery
    • Reduction in consumption
    • Development of alternative materials and technologies.

The Environment

  • Definition: The sum total of external conditions and influences that affect the development and life of an organism.
  • Physical and Biological Factors:
    • Physico-Chemical: Water, air, soil, noise, radiations
    • Biological: Terrestrial and aquatic life
    • Cultural: Historical beliefs, attitudes, practices
    • Socio-economic: Population, economy, infrastructure

Environmental Engineering

  • Definition: The application of theories of science and material forces to confront ecological and socio-economic problems.
    • Focuses on pollution control in water, soil, and air.

UNIT 2: Ecological Concepts

  • Ecology: The study of relationships between living organisms and their environment.
    • Ecosystem: A self-sustaining, self-regulating community of organisms interacting with their environment.
    • Population: Group of the same species in a given locality.
    • Community: Interacting populations of different species.
Ecosystem Characteristics
  • Include movement of energy and materials, self-regulating nature, and continuous input of energy (mostly from sunlight).
  • Ecosystem boundaries are not clearly defined.
  • Energy flow in ecosystems follows the Laws of Thermodynamics.
Habitat and Niche
  • Habitat: The space where an organism lives.
  • Niche: The role an organism plays in its environment, including interactions and modifications to its surroundings.
Organism Interactions

  • Predation: One organism (predator) kills and eats another (prey).

    • Adaptive strategies for prey survival include breeding more and better adaptations.

  • Competition: Two organisms striving for the same limited resource.

    • Two types:
    • Intraspecific Competition (same species)
    • Interspecific Competition (different species)
    • Competitive Exclusion Principle indicates no two species can occupy the same niche simultaneously.
Symbiosis
  • Close, long-lasting interactions between species. Three types:
  1. Parasitism: One organism benefits at the expense of the host.
    • Two types: endoparasites (internal) and ectoparasites (external).
  2. Commensalism: One organism benefits while the other is unaffected.
  3. Mutualism: Benefits both species involved, often obligatory.
Roles of Organisms in Ecosystems
  • Producers: Organisms that produce organic material using inorganic substances and sunlight.
  • Consumers: Organisms that consume organic matter for energy. Types:
    • Primary Consumers (herbivores)
    • Secondary Consumers (carnivores)
    • Omnivores (both plants and animals)
    • Decomposers: Organisms that recycle organic matter back into inorganic substances by breaking down dead matter.
    • Scavengers: Consume remains of dead animals.
Trophic Levels and Energy Flow
  • Each step in the energy flow is a trophic level.
    • Producers: First trophic level
    • Herbivores: Second trophic level
    • Carnivores: Third and higher trophic levels
  • Energy transfer follows the second law of thermodynamics; useful energy lost as heat.
  • Estimation of energy at trophic levels can be assessed through biomass measures.
Food Chains and Food Webs
  • Food Chain: A linear sequence of organisms through which energy is transferred.
  • Food Web: A complex network of interconnected food chains.
Energy Laws in Ecosystems
  1. First Law of Thermodynamics: Energy is not created or destroyed but transforms from one form to another.
  2. Second Law of Thermodynamics: In energy transformations, some energy is lost as heat (measured as entropy).

Structure of the Sun

  • Definition: The sun operates as a nuclear reactor, about 109 times the diameter of Earth and 330,000 times its mass.
  • Composition: 98% hydrogen and helium, with traces of heavier elements (carbon, nitrogen, oxygen, etc.).
  • Solar Layers:
    1. Photosphere: The visible surface of the sun, about 500 km thick, with a temperature around 5500 °C.
    2. Chromosphere: A layer about 2000 km thick, ranging from 4000 °C to 20,000 °C.
    3. Corona: The outer layer extending millions of kilometers, reaching temperatures above 1 million °C.
    4. Solar Interior: Composed of three layers: Convective Zone (70% of radius), Radiative Zone (20%-70% radius), Core (hottest part at 15 million °C).

UNIT 3: Environmental Crisis

  • Definition: Various global issues including global warming, ozone layer depletion, floods, air and water pollution, land degradation, etc.
  • Structure of Earth’s Atmosphere: Different elevation layers characterized by temperature variations influencing pollution.
  • Air Pollution: Accumulation of harmful substances in the atmosphere affecting health and the environment; primarily caused by human activities.
  • Acid Rain: Caused by sulfuric and nitric acids resulting in environmental damage; pollution control strategies required.

UNIT 4: Soil Formation and Properties

  • Geologic Processes: Earth’s dynamic changes influenced by various natural events.
  • Soil Profile: Includes horizons such as A horizon (topsoil), B horizon (subsoil), and C horizon (weathered material).
  • Soil Properties: Include texture, structure, moisture, biotic content, and chemical composition, which influence agricultural productivity.

UNIT 5: Environmental Impact Assessment (EIA)

  • Definition: A process that assesses environmental effects of development projects for informed decision-making.
  • Purpose of EIA: To account for environmental considerations in project evaluation and decision-making, identify potential impacts, and streamline implementation processes.

UNIT 6: Basic Water Microbiology and Public Health

  • Microbiological Contaminants: Includes bacteria, viruses, fungi that impair water quality and pose health risks.
  • Coliform Bacteria: Used as indicators of water pollution; fecal coliforms (e.g., E. coli) are indicators of fecal contamination.
  • Water Quality Parameters: Include pH, turbidity, dissolved oxygen, and presence of heavy metals and pathogenic organisms affecting public health.
  • Water Quality and Health: The role of water quality in disease transmission and preventive measures to ensure safe drinking water.