Intro to ENVISCI Notes

Environmental Science

Definition

  • Environmental Science is a dynamic, interdisciplinary field.
  • It studies the interaction between living and non-living components of the environment.
  • It focuses on human impacts on the environment.
  • It examines the conditions, objects, and circumstances surrounding organisms and communities.
  • It explores the complex interactions within environmental systems.

Interdisciplinary Nature

  • Hierarchy
    • Organismal: How does an organism adapt to extremes?
    • Population: Is the population increasing or decreasing? Why? What controls population size?
    • Community: Who eats whom? What happens to the community when you remove a top predator?
    • Ecosystems: What controls the flow of energy and nutrients through an ecosystem?
    • Biosphere: How is the biosphere responding to increasing atmospheric carbon dioxide levels?
  • Concept
    • Descriptive
    • Functional
    • Evolutionary
  • Taxonomy
    • Plant
    • Microbial
    • Fungal
    • Animal
    • Avian
    • Protozoan
  • Time/Place
    • Marine
    • Terrestrial
    • Freshwater
    • Paleoecology
    • Tropical Ecology
  • Processes
    • Behavioral
    • Physiological

Modern View

  • Environmental Science intersects with:
    • Natural Sciences
    • Social Sciences
    • Humanities

Why Study Environmental Science?

  • Human behavior directly affects the environment.
  • Understanding scientific principles behind natural interactions is essential.
  • Our future depends on our capacity to evaluate and act on environmental evidence.

Facing Global Challenges

  • Climate change
  • Habitat loss
  • Population growth
  • Rapid development

Complex Environmental Systems

  • Involve interactions between natural and human components.
  • Links from local to global, and short- to long-term perspectives.
  • Considers scales from individual behavior to collective action.

The Tragedy of the Commons (Garrett Hardin, 1968)

  • A situation where individuals, acting in their own self-interest, collectively overexploit shared, limited resources.
  • This leads to long-term ruin for all.
  • Rational behavior at the individual level results in irrational outcome at the collective level.
  • "Freedom in a commons brings ruin to all."
  • Without restraints or ethics guiding use, shared resources will inevitably be depleted or destroyed.

Real-World Applications of the Commons

  • Overgrazing of public lands
  • Deforestation in shared forests
  • Overfishing in oceans
  • Water pollution from sewage dumping
  • Air pollution from shared atmosphere

Examples of Environmental Questions

  • How does deforestation influence the global climate?
  • How does deforestation influence the water supply to neighboring towns?
  • How does acid rain influence forest productivity?
  • What are the biological controls over rock weathering?

The Climate Crisis as a Commons Tragedy

  • Commons Affected: The atmosphere
  • Issue: CO2CO_2 emissions from burning fossil fuels
  • Short-term economic gain per country leads to long-term global environmental cost.
  • Countries, like the herders, act in their own interest, leading to climate degradation that affects everyone.

Global Environmental Stress — Key Indicators

  • Forests
    • Deforestation: 1 million hectares lost annually (1980–1990)
    • Main driver: Agricultural land clearing by farmers
    • Concern: Forest degradation from overuse and lack of regulation
  • Soil
    • 10% of vegetated land is moderately degraded
    • 20% of irrigated land is losing productivity
    • Issue: Long-term food security and soil sustainability
  • Fresh Water
    • 20% of global population lacks access to safe drinking water
    • 50% lacks safe sanitation
    • By 2025: 2/3 of world population may face water stress
  • Marine Fisheries
    • 25% of fisheries at max capacity; 35% overfished
    • Pressure to increase harvest through aquaculture
    • Risk: Pollution, wetland and mangrove loss
  • Biodiversity
    • Threats: Habitat destruction and pollution
    • Estimated species: ~14 million
    • 1–11% species risk extinction every decade
    • Coastal ecosystems especially at risk
  • Atmosphere
    • Human activity affects climate (IPCC finding)
    • CO2CO_2 emissions rising in industrialized nations
    • Countries failed to meet 1990 emission targets by 2000
  • Toxic Chemicals
    • 100,000+ commercial chemicals, mostly untested for impact
    • Persistent organic pollutants (POPs): Found worldwide
    • Risk: Toxicity, long-term ecological harm
  • Hazardous Wastes
    • Heavy metal pollution from mining/industry
    • Radioactive contamination incidents increasing
    • Legacy nuclear waste poses long-term threats
  • Waste Management
    • Domestic/industrial waste increasing globally
    • Developed countries: Per capita waste tripled in 20 years
    • Developing countries: Waste expected to double next decade
    • Poor sanitation still a major cause of illness and death