AQA A-Level Environmental Science Past Papers & Mark Schemes

Paper 2's policy and management questions are where marks are most frequently lost through descriptive rather than analytical responses. When a question asks you to evaluate a carbon pricing scheme or an international climate agreement, the mark scheme rewards analysis of why the policy works or fails — examining economic incentives, political feasibility, distributional equity, and technological readiness — not a description of what the policy involves. Build a template for policy evaluation: mechanism (how does it work?), effectiveness (does it achieve its goal? What evidence exists?), limitations (who resists it? What does it not address?), alternatives (what else could achieve the same aim?). Biogeochemical cycles link both papers and are the subject's most reliably examined core knowledge. For the carbon cycle, know the exact processes by which carbon moves between each reservoir: photosynthesis (atmosphere to biosphere), respiration and decomposition (biosphere to atmosphere), combustion (lithosphere/biosphere to atmosphere), ocean absorption (atmosphere to hydrosphere), carbonate formation (hydrosphere to lithosphere). For the nitrogen cycle, know the roles of nitrogen-fixing bacteria (Rhizobium in legume root nodules and free-living Azotobacter), nitrifying bacteria, denitrifying bacteria, and the human disruption through Haber-Bosch synthesis. For the phosphorus cycle, know why it lacks an atmospheric stage and what this means for its cycling rate. Quantitative questions require correct units throughout. Environmental calculations use a wide variety of units — energy in kWh or MJ or kJ/mol, concentrations in mg/l or ppm or μg/m³, areas in km², ecological measures in species per hectare. Always state units at each step of a calculation and double-check at the end that your answer has physically plausible magnitude — an answer suggesting a lake contains 500 tonnes of phosphate per litre should prompt you to recheck. Case study specificity separates high-scoring from mid-scoring responses. Examining statements like 'tropical rainforests contain high biodiversity' score poorly; specific examples with quantitative data — naming a specific ecosystem, citing measured species counts, referencing rates of deforestation — score well. Build a bank of quantitative facts for 5–6 different biomes or environmental contexts.