Sustainability, Ecology and Environmental Ethics: Key Concepts
1.1 Sustainability
Sustainability: possibility that human and other life will flourish on the planet forever (Ehrenfeld). Sustainable development (Brundtland Report, 1987): meeting present needs without compromising future generations’ ability to meet their own needs.
Triple Bottom Line (Elkington, 1997): Planet = ecological; People = social; Prosperity = economic. Nested model: biosphere → society → economy; society and economy depend on nature.
System: connected elements forming a whole. Emergence: properties arising from interactions. Systems thinking: studies connections, feedback and how changes affect the whole. Positive/reinforcing feedback amplifies change; negative/balancing feedback counteracts change. Example: ice melts → darker ocean absorbs more sunlight → more warming.
Resilience: ability to absorb disturbance and retain/recover essential functions. Modularity: groups connected internally but less connected to other groups. Tipping point: threshold after which small changes can cause rapid, major or difficult-to-reverse shifts. Complex adaptive system: interacting components that adapt and self-organize.
Natural capital: stock of natural resources/ecological systems. Ecosystem services: benefits from ecosystems, including food, materials, pollination, nutrient cycling, air/water purification, waste absorption and climate regulation. Biocapacity: ability to regenerate resources and absorb waste. Ecological footprint: human demand on productive land/water for resources and waste. Carrying capacity: population/activity an environment can support over time. Overshoot: demand exceeds ecological regeneration/absorption.
Limits to Growth (1972): modeled population, industry, agriculture, resources and pollution; warned about overshoot on a finite planet. Daly’s four conditions: maintain ecosystem health; use renewables no faster than regeneration; use non-renewables no faster than renewable substitutes can replace them; release waste no faster than ecosystems safely absorb it.
Planetary boundaries (Rockström et al., 2009): climate change; biosphere integrity; biogeochemical flows; ozone depletion; ocean acidification; freshwater change; land-system change; atmospheric aerosols; novel entities. Lecture: 6 of 9 crossed in 2023. Holocene: relatively stable recent epoch. Anthropocene: proposed term for major human influence on Earth. Great Acceleration: rapid increase in human activity after mid-1900s. Wicked problems: complex, connected, evolving problems.
1.2 History and Policy
1713 — Hans Carl von Carlowitz: sustainable forestry/timber supply. Henry David Thoreau: simplicity, Walden. George Perkins Marsh: Man and Nature (1864), human environmental damage. Charles Darwin: evolution/interdependence. John Muir: preservationism, intrinsic value of wilderness, national parks/Sierra Club. Gifford Pinchot: conservation, “wise use” of resources. Aldo Leopold: Land Ethic; humans are members of the biotic community. Rachel Carson: Silent Spring (1962), pesticide harms. Paul Ehrlich: The Population Bomb (1968). Greenpeace: founded in Vancouver in 1971.
Timeline: 1972 Stockholm Conference/UNEP and Limits to Growth; 1983 WCED formed; 1987 Brundtland Report/Our Common Future and Montreal Protocol (CFCs/ozone); 1992 Rio Earth Summit—Agenda 21, biodiversity convention, UNFCCC; 1997 Kyoto Protocol; 2015 Sustainable Development Goals (17 goals to 2030) and Paris Agreement. Canada: Clean Air Act (1971); environmental assessment; CEPA (1988).
Preservationism: protect nature from development/use. Conservation: manage/use resources wisely. Path dependency: present policies/institutions shaped by past decisions. Institutions: rules/norms shaping behaviour. Environmental policies can set standards, restrict harmful activities, protect species/areas, create incentives and coordinate action.
2.1 Environmental Ethics — Textbook Ch. 3
Environmental ethics: moral relationships between humans and nature; asks what has value, who/what deserves moral consideration and what duties humans have.
Instrumental value: useful as a means (forest = timber). Intrinsic value: valuable in itself. Relational value: value through relationships, identity, care and responsibility.
Anthropocentrism: human-centred. Biocentrism: moral consideration for living beings. Ecocentrism: ecological wholes and ecosystem integrity. Utilitarianism: judge consequences; greatest overall benefit/least harm. Deontology: duties, rights and rules regardless of outcome.
Leopold’s Land Ethic: ethical concern includes soils, waters, plants, animals and the biotic community.
Animal rights: animals are sentient and can suffer. René Descartes: animals lack sentience/moral standing (historical view). Jeremy Bentham (1789): ability to suffer matters morally. Peter Singer: animal liberation; rights based on capacity for suffering. Tom Regan: animal rights based on sentience. Speciesism: dismissing animals’ interests because they are another species. Human demands include food, fashion, entertainment and experimentation.
Jurisdiction: court’s authority to hear a case. Standing: right to bring/appear in court. Christopher Stone (1972), “Should Trees Have Standing?”: argued for legal rights/standing for natural objects; linked to Sierra Club v. Morton and Mineral King Valley. Environmental racism: disproportionate exposure of racialized communities to environmental hazards. Ethical analysis: identify affected people/nature, values, who benefits/gets harmed, who decides and long-term trade-offs. Indigenous worldviews are diverse; do not treat them as one uniform belief system.
2.2 Biosphere — Textbook Ch. 4
Atmosphere = air; hydrosphere = water; lithosphere/geosphere = land, rock, soil; biosphere = zone of life; cryosphere = frozen water. Earth systems interact. Ecosystem: organisms interacting with their physical environment. Habitat: where an organism lives. Biome: large region with characteristic climate and life. Biodiversity: genetic diversity (within species), species diversity and ecosystem diversity.
Energy: ability to do work; changes form and flows one way through systems, eventually dissipating as heat. Main constant energy sources: Sun and deep-Earth heat. First law of thermodynamics: energy cannot be created/destroyed, only transformed. Second law: entropy/disorder increases; useful energy disperses as heat. Matter: physical substances/atoms; matter is recycled, and Earth is nearly a closed system for matter. Energy flows; matter cycles.
Food web: feeding connections between organisms. Producers capture energy, usually sunlight; consumers eat organisms; decomposers break down organic matter and recycle nutrients. Energy is lost as heat at each trophic transfer.
CHNOPS: carbon, hydrogen, nitrogen, oxygen, phosphorus, sulphur—key elements for life. Atoms contain protons (+), neutrons (neutral), electrons (−); elements are defined by proton number.
Carbon cycle: photosynthesis takes CO₂ into plants → feeding transfers carbon → respiration/decomposition release carbon → oceans, rocks and fossil fuels store it → combustion releases stored carbon. Nitrogen cycle: fixation makes nitrogen usable → plants absorb it → animals eat plants → decomposition returns nitrogen to soil → bacteria return nitrogen to atmosphere.
Ecosystem services: provisioning = food, freshwater, timber; regulating = climate, pollination, flood control, purification; cultural = recreation, identity, spiritual values; supporting processes = soil formation, nutrient cycling, primary production. Natural capital = underlying stock; ecosystem services = benefits/flows. Damaging natural capital can reduce future services.
3.2 Human Sphere and Impact — Textbook Ch. 5
Human sphere: population, consumption, technology, economy, infrastructure, institutions and land-use choices interacting with natural systems.
IPAT: I = P × A × T. Impact = Population × Affluence (consumption per person) × Technology (impact per unit consumption). Technology can increase impacts (fossil fuels/plastics) or reduce them (renewables/efficiency). Impact is not caused by population alone.
Anthromes: human-shaped terrestrial systems created by population and land-use patterns, such as farms and settlements.
Major biodiversity-loss drivers (HIPPO): Habitat loss/fragmentation; Invasive species; Pollution; Population pressure; Overharvesting/overexploitation. Also remember climate change and land/sea-use change.
Ecological footprint: resource demand and waste absorption linked to lifestyles/products/supply chains. Linear economy: take → make → use → waste. Circular economy: reduce, repair, reuse, share, remanufacture and recycle; recycling alone does not eliminate overconsumption.
GDP: monetary value of final goods/services produced within a country over a period. Formula: GDP = C + I + G + (X − M); consumption + investment + government spending + exports − imports. GDP measures economic activity, not overall well-being, equity or ecological health.
Growth: quantitative increase in economic output. Development: qualitative improvement in human capabilities/quality of life. GDP can rise while pollution, inequality and natural-capital loss also rise. HDI: health/life expectancy, education/knowledge and income/standard of living.
Common-pool resource: difficult to restrict access to; one person’s use reduces availability for others. Commons: resource + community + rules. Good governance involves accountability, transparency, participation, cooperation and feedback.
4.1 Human Health and Justice
WHO definition of health: complete physical, mental and social well-being, not merely absence of disease. Public health: prevention/population health. Healthcare: treatment/individual disease management.
Health is affected by air pollution, climate/heat, unsafe water, toxic contaminants, housing, food access, working conditions, green space and access to services. Healthy environments support human well-being.
Grassy Narrows: mercury pollution from an upstream paper mill contaminated the river, harming ecosystems, fish/food, livelihoods and health across generations. Environmental, health and justice issue.
Poverty penalty: extra burdens associated with poverty, including poor housing, food insecurity, pollution exposure, stress and reduced access to services. Bandwidth tax: chronic scarcity consumes mental energy and makes long-term planning harder. Cycle: low income → poor housing/food/stress → illness/expenses → income falls → deeper poverty.
Urban green spaces: support stress recovery, physical activity, social connection and shade. Maslow’s hierarchy: physiological needs → safety → belonging → esteem → self-actualization.
One Health: human, animal, plant and ecosystem health are interconnected. Example: farm runoff → contaminated water → harms people, animals, plants and aquatic ecosystems.
Economic inequality: unequal income, wealth, resources or opportunities. Equality: same support. Equity: support based on need. Justice: remove systemic barriers and create fair outcomes.
Environmental justice: fair distribution of environmental benefits/harms and meaningful participation in decisions. Distributional justice: who receives benefits/burdens. Procedural justice: who participates/has a voice. Recognition justice: whose identities, histories, rights and knowledge are respected. Climate justice: responsibility for climate change, unequal impacts and unequal capacity to respond.
Doughnut Economics (Kate Raworth): safe/just space between the social foundation (food, water, health, housing, education, political voice) and ecological ceiling (planetary boundaries).
4.2 Climate and Climate Change
Weather: short-term atmospheric conditions. Climate: long-term weather patterns, typically 30+ years. Climate change: long-term shifts in temperature/weather; current rapid warming is primarily human-caused. IPCC (1988): assesses/synthesizes climate research, impacts and risks.
Evidence: thermometer records; proxies such as ice cores, tree rings, corals, sediments, fossils and stalagmites; warming oceans, sea-level rise, melting glaciers/ice sheets/permafrost, heat waves and species-range shifts.
Natural drivers: continental plate movement, volcanism and Milankovitch cycles—changes in Earth’s tilt, axial wobble/precession and orbit shape.
Greenhouse effect: greenhouse gases absorb/re-emit outgoing infrared radiation, trapping heat. Incoming solar radiation is short-wave; outgoing radiation is long-wave. Natural greenhouse effect supports life; extra human-caused gases strengthen it. Gases: water vapour, CO₂, methane, nitrous oxide, ozone and industrial gases.
Human sources: fossil fuels, deforestation, industry/cement and agriculture. Carbon stores: atmosphere, biosphere, hydrosphere and lithosphere. CO₂ persists a long time; lecture estimates CO₂ ~300–1,000 years, methane ~12 years, nitrous oxide ~120 years. Arctic amplification: Arctic warms faster than global average. Sea-level rise: thermal expansion of warming water + melting land ice.
Impacts: heat/extreme weather, changed precipitation/water availability, ocean warming/acidification, melting ice, ecosystem shifts, food/water insecurity, health effects, migration and economic damage. Cascading effects: heat/drought → crop loss → food shortages/prices rise → health/economic impacts.
Mitigation = reduce causes/emissions: renewable energy, efficiency, cleaner transport/buildings, forest protection, reduced emissions and carbon capture. Adaptation = prepare for effects: heat plans/shade, flood protection, coastal restoration, resilient crops/infrastructure. Both are needed. Carbon sink: absorbs more CO₂ than it releases (forests, oceans, soils).
Agreements: UNFCCC (1992) = international climate framework; Kyoto Protocol (1997) = targets for participating countries; Paris Agreement (2015) = hold warming well below 2°C and pursue 1.5°C, with countries setting NDCs. Montreal Protocol (1987) phased out ozone-depleting substances such as CFCs; do not confuse ozone protection with climate agreements.
5.1 Freshwater Systems (Textbook Ch. 8)
Freshwater: water with low salt concentration (typically below 1%). Only ~2.5% of Earth’s water is freshwater; less than 1% is readily available. Most is stored in glaciers, ice caps and groundwater. Surface water: rivers, lakes, wetlands. Groundwater: water beneath Earth’s surface. Aquifer: underground formation storing/supplying groundwater. Watershed: land draining to a common outlet. Water quality: physical, chemical and biological condition. Water quantity: amount available.
Water cycle: evaporation/transpiration → condensation → precipitation → infiltration/runoff → rivers, groundwater, oceans. Freshwater supports drinking, sanitation, agriculture, industry, ecosystems, biodiversity and cultural relationships. Canada’s water is unevenly distributed; large quantities are in northern areas, away from many population centres.
Point-source pollution: identifiable discharge/source. Non-point-source pollution: diffuse sources such as farm/urban runoff. Pollutants include pathogens, nutrients, sediment, pesticides, toxic chemicals, metals and plastics. Eutrophication: excess nitrogen/phosphorus → algal growth → algae die/decompose → oxygen decreases → hypoxia/fish deaths. Other pressures: overuse, dams/diversions, agriculture, urbanization, wastewater and industrial pollution.
Solutions: watershed/wetland protection, less fertilizer and pesticide runoff, wastewater treatment, water conservation, efficient irrigation, water-quality monitoring and habitat restoration. Example: fertilizer runoff → algae increase → decomposition uses oxygen → fish harmed; reduce runoff and protect wetland buffers.
5.2 Oceans
Marine system: saltwater ecosystem; average salinity ~3.5%. Estuary: where freshwater and seawater mix. Oceans cover ~70% of Earth’s surface and hold ~97.5% of its water. They regulate heat and carbon, support biodiversity/food webs, provide food, livelihoods, trade, coastal protection and cultural benefits.
Plastic pollution: organisms ingest plastic or become entangled; plastic breaks into microplastics. Much marine plastic originates on land. Overfishing: removing fish faster than populations recover. Bycatch: unintended organisms caught during fishing. Habitat loss: coastal development damages habitats. Invasive species: introduced species affect native species and ecosystems.
Ocean acidification: ocean absorbs CO₂ → pH decreases and carbonate availability changes → shell/skeleton-building organisms struggle. Coral bleaching: heat stress causes corals to lose symbiotic algae; prolonged stress can cause coral death and reef degradation. Dead zones: excess nutrients → algal growth → decomposition uses oxygen → low oxygen harms marine life. Ocean warming shifts species and disrupts marine ecosystems.
Solutions: reduce plastics/chemical/nutrient runoff, improve wastewater treatment, cut greenhouse gases, protect/restore reefs, estuaries and coasts, sustainable fisheries, marine protected areas, monitoring and respect for Indigenous marine governance.
6.1 Forests, Ecosystems and Biodiversity
Ecosystem: organisms interacting with each other and the physical environment. Biodiversity: variety of life, including genetic, species and ecosystem diversity. Species richness: number of species. Species evenness: how evenly individuals are distributed among species. Habitat diversity: variety of habitats. Biomass: total mass of living/recently living organisms. Biodiversity supports ecosystem functioning and resilience.
Trophic levels: producers → herbivores → carnivores → apex predators. Producers/autotrophs: make their own food. Consumers: eat organisms. Decomposers: break down organic matter and recycle nutrients. Energy generally decreases at higher trophic levels. Keystone species: species with a major influence on ecosystem structure. Trophic cascade: effects spread through food-web levels when a species changes or disappears.
Biome: large region with characteristic climate, soil and organisms. Taiga/boreal forest: conifers, relatively low biodiversity. Mixed/Great Lakes forest: hardwoods, greater biodiversity. Eastern broadleaf deciduous forest: broadleaf trees, seasonal leaf loss. Pacific temperate rainforest: green year-round. Tropical rainforest: extremely high biodiversity; lecture states >50% of species may occur there despite covering ~6% of land. Tropical deciduous forest: distinct wet/dry seasons. Coniferous: cone-bearing trees. Deciduous: loses leaves/needles during dormancy. Evergreen: retains foliage year-round. Dendrochronology: dating/studying trees using growth rings.
Forests cover roughly one-third of land; humans have removed about half of original forest cover. Forests provide habitat, store carbon, regulate soil/water, support biodiversity and provide resources/livelihoods. Deforestation: long-term conversion of forest to another land use. Disturbance: event changing forest size, structure or composition; some natural disturbance helps maintain forest diversity.
HIPPO biodiversity-loss drivers: Habitat loss/fragmentation; Invasive species; Pollution; Population pressure; Overexploitation. Climate change intensifies pressures. Habitat fragmentation: habitat divided into smaller patches, isolating populations and limiting movement/gene flow.
Forest types: Primary forest: not logged, native species, naturally regenerated. Production forest: logged at least once or actively logged. Plantation forest: commercially selected trees deliberately planted. Non-timber forest products: maple syrup, mushrooms, medicinal compounds, wreaths/Christmas trees.
Solutions: conservation/protected areas, Indigenous Protected and Conserved Areas (IPCAs), 30×30 target (conserve 30% of land and water by 2030), restoration ecology (repair damaged ecosystems), reforestation, invasive-species removal, reconciliation ecology (human–wildlife coexistence), wildlife corridors/connectivity, sustainable forest management and Indigenous stewardship.