Environmental Systems and Societies Study Guide

Perspectives and Worldviews

• Perspectives: A perspective is the specific view an individual holds regarding a situation, shaped by personal and collective assumptions, values, and beliefs. These are informed by sociocultural norms, scientific understanding, laws, religion, and lived experiences.

• Values: Principles or qualities that individuals or groups deem important. Organizational values are often reflected in policies, media, and advertisements.

• Worldviews: The shared lenses through which groups perceive and act within their environment, shaped by culture, ideology, and politics.

• Environmental Value Systems (EVS): A model representing the inputs (socialization, media, education) that affect our perspectives and the resulting outputs (decisions, actions).

The Spectrum of Environmental Philosophies

1. Ecocentrism:

   • Holistic and Earth-centered.

   • Views nature as having intrinsic value regardless of its utility to humans.

   • Favors self-sufficiency, low-tech lifestyles, and restraint in resource use.

   • Deep Ecologists: Extreme ecocentrists who believe in the pre-eminent importance of nature.

2. Anthropocentrism:

   • Human-centered.

   • Believes humans must sustainably manage the global system through regulation and taxes.

   • Nature exists primarily for human benefit.

3. Technocentrism:

   • Technology-centered.

   • Believes technological developments can provide solutions to all environmental problems.

   • Advocates for unlimited economic growth despite finite resources.

The Environmental Movement

• Historical Roots: Concerns regarding pollution and conservation date back to the Romans and ancient practitioners in China, India, and Peru.

• Modern Movement: Catalyzed by Rachel Carson’s Silent Spring (1962), which highlighted the accumulation of DDT in food chains and its carcinogenic risks.

• Key Figures:

  • Greta Thunberg: Activist who galvanized youth via "Fridays for Future."

  • Sir David Attenborough: Natural historian who documented biodiversity loss and the "Great Acceleration" of human consumption.

  • James Hansen: NASA scientist who testified to Congress in 1988 about rising global temperatures ($0.5^{\circ}C$ to $0.7^{\circ}C$ rise in the 20th century).

  • Dame Ellen MacArthur: Advocate for the circular economy, comparing Earth’s finite resources to those on a solo voyaging boat.

• Major Disasters:

  • Minamata (1956): Methylmercury poisoning in Japan.

  • Bhopal (1984): Lethal release of 40 tonnes of methyl isocyanate gas.

  • Chernobyl (1986): Level 7 nuclear meltdown spreading isotopes of caesium, strontium, and iodine.

  • Fukushima (2011): Tsunami-induced nuclear disaster highlighting human error in safety design.

Systems and Models

• System Definition: A set of interacting parts forming a whole. Scale ranges from an individual cell to the entire Earth.

• Components:

  • Storages: Represented by rectangular boxes.

  • Flows: Represented by arrows (inputs and outputs).

  • Transfers: Movement of matter/energy without changing state (e.g., water moving from river to sea).

  • Transformations: A change of state or chemical nature (e.g., photosynthesis converting light to matter: $6CO<em>{2} + 6H</em>{2}O \rightarrow C<em>{6}H</em>{12}O<em>{6} + 6O</em>{2}$).

• Energy Laws:

  • First Law of Thermodynamics: Energy cannot be created or destroyed, only transformed.

  • Second Law of Thermodynamics: Energy transformations are inefficient; entropy increases as biomass passes through food chains, often lost as heat.

• Feedback Loops:

  • Negative Feedback: Stabilizing; counteracts deviation (e.g., predator-prey cycles like the Canadian lynx and snowshoe hare).

  • Positive Feedback: Destabilizing; amplifies change toward a tipping point (e.g., Arctic ice melt reducing albedo, causing more warming).

• Resilience: The ability of a system to return to its initial state after a disturbance. Higher diversity and storage size increase resilience.

Sustainability and Environmental Justice

• Sustainability: The long-term viability of a system, balancing the three pillars: Environmental, Social, and Economic.

• Natural Capital vs. Natural Income: Natural capital is the stock (e.g., a forest), while natural income is the yield (e.g., timber) that can be harvested sustainably.

• Ecological Footprint (EF): The area of land/water required to provide resources and assimilate waste for a population. If EF > Biocapacity, the system is in ecological overshoot.

• Environmental Justice: The principle that all people deserve a pollution-free environment and equitable resource access regardless of race or income.

• Global Models:

  • UN Sustainable Development Goals (SDGs): 17 goals to guide global action by 2030.

  • Planetary Boundaries: Defines 9 safe operating limits for Earth (e.g., Biosphere Integrity, Biogeochemical flows of Nitrogen and Phosphorus).

  • Doughnut Economics: A framework for a regenerative economy that stays within an "ecological ceiling" while meeting a "social foundation."

  • Circular Economy: Designing out waste and keeping materials in use.

Ecology: Populations and Communities

• Niche: The particular set of abiotic and biotic conditions required by a species. No two species can occupy the exact same niche (Competitive Exclusion Principle).

• Population Growth:

  • J-curves: Exponential growth (boom and bust).

  • S-curves: Growth limited by Carrying Capacity ($K$), the maximum number of individuals an area can sustainably support.

• Trophic Levels: Positions in a food chain (Producers, Primary Consumers, etc.).

• Ecological Efficiency: Typically only $10\%$ of energy is passed between levels.

• Bioconcentration:

  • Bioaccumulation: Build-up of non-biodegradable toxins (DDT, mercury) within an organism over time.

  • Biomagnification: Increasing concentration of toxins as one moves up the food chain.