Human Impact and Sustainability
What this domain tests
Human Impact and Sustainability asks you to evaluate how human activities alter ecosystems and how societies can reduce harm. Questions cover greenhouse gases, climate change, pollution, habitat loss, biodiversity, resource use, renewable and nonrenewable energy, and sustainable design. You should connect a human action to an ecological consequence and a feasible mitigation strategy.
Core rules
- Burning fossil fuels releases CO2; agriculture and waste release methane; fertilizer use releases nitrous oxide.
- Greenhouse gases trap heat, warming the atmosphere and oceans; ocean uptake increases acidification.
- Habitat destruction and fragmentation are major causes of biodiversity loss.
- Eutrophication occurs when excess nutrients cause algal blooms, decomposition, and oxygen depletion.
- Sustainability meets present needs without reducing future options.
- Mitigation reduces causes; adaptation reduces harm.
Worked example
Fertilizer containing nitrogen and phosphorus washes into a pond. Explain the likely sequence and a management strategy. Reasoning: Excess nutrients limit algal growth, so algae bloom. When algae die, decomposers break them down and consume dissolved oxygen. Low oxygen stresses fish and other aerobes, sometimes causing kills. A buffer strip of vegetation can intercept runoff before it reaches the pond. The explanation must link nutrient input, bloom, decomposition, oxygen decline, and ecological harm.
Traps
- Confusing weather with climate; a cold week does not disprove a warming trend.
- Confusing ozone depletion with climate change; these are different problems.
- Assuming renewable energy has zero environmental impact.
- Treating all pollution as visible; CO2 and excess nutrients can be invisible.