Environmental Science Notes

Environmental Value Systems (EVS)

  • Definition: A paradigm that shapes how individuals/groups perceive and evaluate environmental issues.
  • Conservationist: Focus on conserving nature to sustainably supply goods and services.
  • Preservationist: Advocates for the unconditional conservation of nature for its intrinsic spiritual value.

Environmental Movement Timeline

  • Neolithic Agricultural Revolution (10,000 years ago)
    • Population began to rise as humans transitioned to farming.
  • Industrial Revolution (Early 1800s)
    • Increased population growth and resource use; medical advancements led to increased life expectancy.
  • Green Revolution (1940s-1960s)
    • Application of technology in agriculture that dramatically increased food production. Featured increased global population to approximately 3 billion.
  • Modern Environmental Movement (1960s onwards)
    • Formation of NGOs like Greenpeace (1971) and the first Earth Summit in 1972 highlighted issues like global warming, deforestation, and the decline of fish populations.

Ecological Perspectives

  • Ecocentric: Values nature; promotes intrinsic value and self-sufficiency of societies.
  • Anthropocentric: Focus on human benefits in decision-making; promotes strong regulatory actions.
  • Technocentric: Beliefs that technology can resolve environmental issues; important for economic growth.
  • Key Figure: Rachel Carson, author of "Silent Spring" (1962), criticized the indiscriminate use of pesticides.

Environmental Landmarks

  • Montreal Protocol (1987): Agreement to phase out ozone-depleting substances.
  • Kyoto Protocol (1992): International agreement for reducing greenhouse gas emissions.
  • COP 21 Paris Agreement (2015): Global treaty to combat climate change.

Case Studies

  1. Bhopal Disaster (1984): Pesticide plant explosion that released methyl isocyanate gas; considered the worst industrial disaster.
  2. Minamata Bay (Japan): Mercury poisoning due to industrial waste leading to severe health issues.
  3. "Should I Eat Meat?": Examines how different religious value systems (Hindus, Muslims, etc.) view meat consumption.
  4. Seed Hunter: Focus on the vulnerability of chickpeas and the role of genetic engineering.
  5. Vanishing Lions: Study of anthropocentric solutions where tourism promotes coexistence between humans and lions.

Systems & Models

  • Definition: A system is a set of interrelated parts working together; can be living or nonliving.
  • Types of Systems:
    • Open System: Exchanges energy and matter with surroundings (e.g., most living systems).
    • Closed System: Exchanges energy but not matter (e.g., biogeochemical cycles).
    • Isolated System: Exchanges neither (e.g., the universe).
  • Models: Simplified representations of reality; can indicate patterns but may lose accuracy over long-term predictions.
  • Transfers vs. Transformations:
    • Transfers: Movement of energy or matter that changes location but not state.
    • Transformations: Changes in the state/chemical nature (e.g., photosynthesis).

Energy & Equilibria

  • First Law of Thermodynamics: Energy cannot be created or destroyed, only transformed.
  • Second Law of Thermodynamics: In an isolated system, entropy increases over time, representing disorder.
  • Efficiency: Ratio of useful work performed to total energy consumed.
  • Equilibrium:
    • Steady State: Continuous inputs and outputs of a system that stabilize (e.g., body temperature).
    • Static: No changes occur (e.g., a pile of books).
    • Stable vs. Unstable: Systems that return to original state vs. those that do not.

Feedback Mechanisms

  • Positive Feedback: Amplifies changes, potentially leading to tipping points (e.g., Albedo Effect).
  • Negative Feedback: Stabilizes systems, counteracting deviations from equilibrium (e.g., global dimming from increased cloud cover).

Resilience & Tipping Points

  • Resilience: Ability to return to initial state after disturbance; complex systems with higher diversity tend to be more resilient.
  • Tipping Points: Critical thresholds where an ecosystem undergoes significant change (e.g., coral reef death).

Sustainability

  • Definition: Managing resources effectively to ensure natural replacement and ecosystem recovery.
  • Natural Capital: Natural resources producing sustainable income; analyzed in the Millennium Ecosystem Assessment (2001).
  • Key Statistics:
    • 25% of fish stocks overharvested.
    • Species extinction rates are 100-1000x background rates.
    • 50% of corals lost or severely degraded.

Issues of the Tragedy of the Commons

  • Concept: Individuals acting in self-interest can deplete a shared resource (e.g., overhunting leading to extinction).
  • Environmental Impact Assessments: Analyzes potential impacts of projects and ways to mitigate negative outcomes.

Pollution

  • Definition: Addition of substances to the environment beyond its natural ability to detoxify.
  • Types of Pollutants:
    • Primary: Directly harmful upon emission (e.g., carbon monoxide).
    • Secondary: Formed through reactions in the environment (e.g., acid rain).
  • Sources:
    • Point Source: Single, identifiable origin (e.g., waste disposal pipe).
    • Non-Point Source: Diffuse origins (e.g., vehicle emissions).
  • Pollution Effects:
    • Acute: Sudden large release (e.g., Bhopal disaster).
    • Chronic: Long-term, small amounts (e.g., air pollution in cities).

Biodegradable Pollutants

  • Break down easily in the environment (e.g., soap).
  • Microbeads: Less than 5mm plastic particles that do not degrade in water, leading to bioaccumulation.

Pollution Detection

  • Direct Detection: e.g., measuring pH, dissolved oxygen.
  • Indirect Detection: Observing changes in biotic and abiotic factors (e.g., water quality indicators).