Ecosystem Services and Climate Sensitivity

Ecosystem Services

• Services provided by ecosystems to humans, including: provisioning services (food, water, fuel), regulating services (climate regulation, flood control), cultural services (recreation, aesthetic experiences), and supporting services (primary production, nutrient cycling), which underpin all others.

Equilibrium Climate Sensitivity

• Expected temperature rise from doubling atmospheric CO2.
• Predicts new global mean near-surface air temperature after CO2 concentration stops increasing.
• Reaching equilibrium temperature can take centuries to millennia after CO2 has doubled.
• Estimated range: 2.5°C to 4°C.

Anthropocene

• Geological epoch where humans are the dominant forces shaping the planet, specifically affecting geology and ecosystems.

Biogeochemical Cycles

• Movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and Earth's crust.
• Reservoir: place where an element is stored.
• Flux: movement of elements between reservoirs.
• Residence time: average time an element stays in a reservoir before moving.
• Sink: reservoir that absorbs more of an element than it releases.
• Source: process or reservoir that releases more of an element than it stores.

Photosynthesis and its Role in the Carbon Cycle

• Equation: 6CO2 + 6H2O → C6H12O6 + 6O2.
• Process where plants, algae, and some bacteria use sunlight to convert carbon dioxide (CO2) and water into glucose and oxygen.
• Removes CO2 from the atmosphere.
• Carbon stored in plants becomes food for animals when they consume plants.
• Carbon in plants becomes part of long-term reservoirs.
• Offsets carbon emissions by absorbing CO2.

Phosphorus Cycle

• Largest reservoir: rocks and sediment.
• Slow cycle.
• On land: found in soils, plants, and animals.
• In the ocean: found in water, plants, and animals.
• Not a gas.
• Fluxes: weathering (rock to soil), runoff (to rivers and oceans), recycling (decomposition of plants and animals back to soil), sedimentation (settling on the ocean floor).
• Human alterations: mining for fertilizers and causing erosion lead to eutrophication (algal blooms depleting oxygen and harming aquatic life) and soil degradation.

Nitrogen Cycle

• Largest reservoir: the atmosphere.
• Fluxes: fixation (bacteria convert atmospheric nitrogen to usable forms), denitrification (bacteria convert nitrogen back to N2 gas, releasing it to the atmosphere), decomposition (organic nitrogen in dead matter returns to the soil), anthropogenic flux (fertilizers and fossil fuel burning increase nitrogen in ecosystems).
• Human alterations: burning fossil fuels and using fertilizers lead to water pollution and biodiversity loss.

Carbon Cycle

• Largest reservoir: rocks and sediment.
• Slow cycle.
• Very little is gas.
• Fluxes: photosynthesis (plants take in CO2 to create organic matter), respiration (plants, animals, and microbes release CO2 back to the atmosphere), decomposition (organic matter breaks down, releasing carbon), anthropogenic flux (fossil fuel burning and land use change release CO2 to the atmosphere), ocean absorption (CO2 dissolves in ocean water and circulates through deep and surface waters).
• Human alterations: burning fossil fuels and deforestation lead to climate change and ocean acidification.

Radiative Forcing

• Change in energy balance of the atmosphere.
• Positive radiative forcing warms the Earth.
• Negative radiative forcing cools the Earth.

Greenhouse Effect (Natural)

• Gases like water vapor, carbon dioxide (CO2), and methane (CH4) trap heat in the atmosphere, warming the Earth.
• Keeps the Earth from freezing.

Climate Feedbacks

• Processes that amplify (positive feedback) or dampen (negative feedback) effects of climate change.
• Positive: water vapor feedback (higher temperature means more water vapor).
• Negative: ice-albedo feedback (melting ice reduces Earth's reflectivity).

IPCC (Intergovernmental Panel on Climate Change)

• Assesses scientific research on climate change to provide comprehensive reports to policymakers.

Observed Changes in Climate System

• Warming: increase in temperatures.
• Sea level rise: driven by melting glaciers and ice sheets.
• Precipitation patterns: increased variability, droughts, and storms.
• Melting Arctic ice and glaciers: reduction in Arctic sea ice.
• Ocean acidification: absorption of excess CO2 by oceans, lowering their pH.

Economic Terms

• Economic Optimum: marginal revenue = marginal cost (adding more effort would result in a loss in net benefits).
• Open Access Equilibrium: total cost = total revenue (so many people that net revenue is zero).
• Social Optimum: Market equilibrium when accounting for externalities.
• Market equilibrium: demand = supply.

External Costs/Benefits

• External costs (negative externalities): costs to third parties during production or consumption (e.g., farmer has dead plants because of a nearby steel factory).
• External benefits (positive externalities): benefits received by third parties in a transaction (e.g., land preservation, vaccines).
• Internalization of externalities: incorporating external costs or benefits into market prices.
• Market failure: when externalities are not internalized in market prices (e.g., cars pollute but you don't pay extra to offset the pollution).
• Addressing externalities: Pigovian tax (targets cost of externality), Cap-and-Trade (limited permits for pollution, companies can trade), Direct Regulation (government sets legal limits), Subsidies for clean tech, Coase theorem (private negotiation).

Coase Theorem

• Parties can negotiate without government intervention if property rights are well defined.

Optimal Pollution

• Level of pollution where the marginal social benefit of production equals the marginal social cost, including external costs of pollution.
• Acknowledges that achieving zero pollution would require ceasing all production.
• Optimal pollution increases if demand increases.

Tragedy of the Commons

• Dilemma where several people, acting independently and rationally in their own self-interest, will inevitably deplete shared limited resources even if it's not in anyone's long-term interest. (e.g., overfishing).
• Common good: a common resource open to everyone (e.g., ocean or atmosphere).
• Going beyond the boundary results in ecological overshoot, causing environmental degradation like climate change, ocean acidification, and biodiversity loss.

GPI vs. GDP

• GDP measures the value of all goods and services produced in a country, but doesn't subtract costs of pollution, deforestation, or resource depletion.
• GDP ignores well-being, inequality, or unpaid work and focuses only on economic growth, even if it harms the environment and social health.
• Genuine Progress Indicator (GPI) is an alternative that offers a better picture of well-being by adding factors like volunteer work, household labor, and access to education.
• GPI subtracts harmful things like pollution, crime, and income inequality.
• GPI reflects the need to preserve natural resources unlike GDP which rewards resource exploitation.
• GPI measures well-being by including happiness, health, and equality, showing quality of life, not just money made.
• GPI accounts for environmental damage, pushing for sustainable policies like clean energy and conservation.
• GPI adjusts for inequality, showing if economic gains benefit everyone, not just the rich.

This quiz explores ecosystem services provided to humans, including provisioning and regulating services. It also delves into equilibrium climate sensitivity, predicting temperature changes due to atmospheric CO2 levels. Learn about the Anthropocene epoch and biogeochemical cycles that impact our planet's health.