A-Level Geography: Climate Change — Causes, Impacts and Responses

Climate change runs through A level Geography: it is part of the water and carbon cycles core theme, a named debate in OCR's geographical debates paper, and a thread in Pearson Edexcel's carbon cycle and energy security topic. This material brings together the causes, impacts and responses that all these routes share, with attention to the reasoning examiners reward: evidence, attribution and evaluation.

It starts with causes. You distinguish the natural greenhouse effect, which keeps the planet habitable, from the enhanced greenhouse effect driven by human emissions of carbon dioxide, methane and nitrous oxide. You meet the natural drivers of past change, the Milankovitch cycles of eccentricity, obliquity and precession, variations in solar output and volcanic aerosols, and use evidence to see why none of them explains the warming of recent decades. Proxy records such as ice cores and tree rings are separated from instrumental measurements.

The impacts section tackles common misconceptions. Melting sea ice barely changes sea level because floating ice already displaces its own weight of water; the rise comes from thermal expansion and melting land ice. Effects on food production are uneven, with some cooler regions gaining while many tropical and dryland regions lose, and the spread of vector-borne disease links climate to health.

Responses are sorted into mitigation, which tackles causes, and adaptation, which manages impacts, with solar radiation management as a controversial third category. Governance questions compare the Kyoto Protocol, with binding targets mainly for developed countries, and the Paris Agreement, which aims to hold warming well below 2 °C and pursue 1.5 °C through nationally determined contributions from all parties. A short per-capita calculation shows why equity arguments look beyond national totals.

The material offers a quiz with explanations, flashcards for the key terms and agreements, a printable written sheet of extended explanations and evaluations, and an oral exam in which an examiner asks one question at a time and gives brief feedback at the end. The carbon cycle itself and its feedbacks are practised in a separate material in this category.

• Distinguish the natural and enhanced greenhouse effects
• Explain natural causes of climate change and why they do not explain recent warming
• Use proxy and instrumental evidence of climate change
• Explain impacts on sea level, food security and health, avoiding common misconceptions
• Classify and evaluate mitigation, adaptation and geoengineering
• Compare the Kyoto Protocol and Paris Agreement and discuss equity in climate action

Practice material written by Zestly, based on climate change content in the DfE GCE AS and A level subject content for geography (water and carbon cycles) and board specifications such as Pearson Edexcel 9GE0 Topic 6.3 and 6.9, OCR H481 geographical debate 'Climate change' and AQA 7037 section 3.1.1.4. Warming figures follow the IPCC Sixth Assessment Report (2021).