Knowledge Organiser: Climate Change
Key Terms
- Enhanced greenhouse effect — human GHG emissions trap more heat
- Mitigation — reducing causes of climate change
- Adaptation — coping with effects of climate change
- Carbon sink — system that absorbs more CO₂ than it releases
- Positive feedback — warming amplifies further warming
- Milankovitch cycles — natural orbital changes over 20,000–100,000 years
- Phenology — study of seasonal biological events as climate indicators
Must-Know Statistics
- CO₂: 421 ppm (2023) — highest in 3 million years; pre-industrial: 280 ppm
- Temperature: 2023 was 1.45°C above pre-industrial baseline; hottest year on record
- Sea level rise: 21–24 cm since 1880; currently rising 3.7 mm/year
- Rhône Glacier: lost 1.4 km in 20 years
- Methane: 28× more potent GHG than CO₂; nitrous oxide: 265×
- Fossil fuel emissions: 38 billion tonnes CO₂/year (2022)
- World Bank climate migration projection: 216 million by 2050
Named Examples
- Paris Agreement (2015): 196 countries; 1.5°C target; NDCs every 5 years
- Germany Energiewende: 59% renewable electricity by 2023
- Norway EVs: 80% of new cars electric in 2023
- Sleipner CCS (Norway): 1M tonnes CO₂/year stored since 1996
- Maldives: $500M sea wall; Hulhumalé island at 2m elevation
- Bangladesh: Floating gardens; BINA Dhan 11 (14 days submerged; 2M farmers)
- Netherlands: Room for the River €2.3bn; 100+ amphibious homes in Amsterdam
Exam Must-Know Points
- Natural causes exist but CANNOT explain modern warming (too slow; wrong direction)
- Mitigation = reduce causes; adaptation = cope with effects — never confuse these
- Always give statistics — "sea levels are rising" scores nothing; specific figures score marks
- Link physical effects to human consequences (sea level → displacement; drought → food insecurity)
- HIC vs LIC adaptation: Netherlands (€2.3bn engineered) vs Bangladesh (low-cost traditional) — both valid but wealth determines scale
- Climate justice: LICs most vulnerable, contributed least to emissions
- Level 3 = named example + specific evidence + supported judgement
Common Mistakes
- Confusing mitigation and adaptation: Mitigation reduces the causes (e.g. renewable energy, carbon capture); adaptation copes with effects (e.g. sea walls, flood-resistant crops) — never swap these terms
- Saying natural causes explain current warming: Milankovitch cycles and solar variation operate over thousands of years and are currently in a cooling phase — they cannot account for rapid warming since 1950
- Vague effects without statistics: "Sea levels are rising" scores 0 at Level 3 — use specific data (21–24 cm since 1880; currently rising 3.7 mm/year) and link to human consequences (216 million climate migrants projected by 2050)
- Ignoring climate justice: Evaluation questions expect you to note that LICs are most vulnerable to climate change but have contributed least to emissions — this is a key point of distinction between L2 and L3 answers
Memory Aid
- 1.5°C — target limit of warming above pre-industrial levels
- 2°C — maximum acceptable warming limit
- 5 years — cycle for reviewing NDCs (Nationally Determined Contributions)
- 196 — number of countries that signed
- CO₂ = 1 (baseline)
- Methane = 28× (livestock, rice, landfill)
- Nitrous oxide = 265× (fertilisers)
- CFCs = thousands× (now largely banned)