The big idea: Mitigation means tackling the causes of climate change — cutting greenhouse-gas emissions or removing carbon dioxide from the air.
It is different from adaptation (2.3.2), which means coping with the effects. Mitigation attacks the source; adaptation manages the impact.
The main mitigation strategies
- International agreements — countries jointly pledge emission cuts (e.g. the Paris Agreement).
- Carbon pricing — carbon taxes and carbon trading make polluting expensive.
- Carbon offsetting — funding emission cuts elsewhere (e.g. tree planting) to balance your own.
- Renewable energy & technology — solar, wind, electric vehicles, carbon capture replace fossil fuels.
- Reforestation & geo-engineering — large-scale removal of CO₂ from the atmosphere.
Source vs impact: If a strategy reduces emissions, it is mitigation.
If it helps people live with the effects (sea walls, drought-resistant crops), it is adaptation — that's the next micro.
Examiners want the mechanism — how a strategy reduces greenhouse gases. Name the strategy, then explain the chain to lower emissions.
| Strategy | How it reduces emissions |
|---|---|
| Carbon trading (e.g. EU ETS) | Caps total emissions and lets firms trade permits → polluting costs money → firms cut emissions |
| Carbon offsetting | Funds projects that absorb or avoid CO₂ (tree planting) to balance emissions made elsewhere |
| Renewable energy | Solar/wind replace fossil-fuel power stations → far less CO₂ per unit of electricity |
| Carbon capture / geo-engineering | Captures CO₂ from power stations or air and stores it → less reaches the atmosphere |
| Regulation & carbon tax | Government rules and taxes make high-carbon activity costly → encourages low-carbon choices |
Answering an 'Explain' [4]
- Name the strategy (e.g. invest in renewable energy).
- Give the mechanism — how it works (replaces fossil-fuel power stations).
- Link to emissions (so less CO₂ is released). 2 marks per developed strategy.
Memorize terms 3x faster
Smart flashcards show you cards right before you forget them. Perfect for definitions and key concepts.
Try Flashcards Free7-day free trial • No card required
EU Emissions Trading System (carbon trading): The EU ETS caps total emissions from heavy industry and power, issuing tradable permits.
Effect: firms that cut emissions can sell spare permits; heavy polluters must buy more — a financial reason to decarbonise. EU ETS-covered emissions have fallen markedly since 2005.
Costa Rica (renewables + reforestation): Costa Rica generates close to 99% of its electricity from renewables (mostly hydro, plus geothermal and wind) and pays landowners to protect forests.
Effect: very low-carbon power and forests that absorb CO₂ — mitigation at both the source and the sink.
The Paris Agreement (international): Under the 2015 Paris Agreement almost every country pledged emission cuts to keep warming well below 2 °C.
Effect: a shared framework and national targets — though success depends on countries actually meeting their pledges.
Name a real scheme: Top markband answers name a real scheme (EU ETS, Costa Rica, Paris Agreement) and give its effect — not just 'use renewables'.
How this is tested: Paper 2, Section B ends with a [10]-mark 'to what extent / discuss' essay, marked on markbands.
Top band needs: accurate terminology, named case studies, a balanced two-sided argument, and a justified conclusion. (Section A also tests Explain [4] strategies and Describe [2] data.)
| Year | Offsets (Mt CO₂e) |
|---|---|
| 2010 | 40 |
| 2014 | 55 |
| 2016 | 60 |
| 2018 | 100 |
| 2021 | 160 |
IB-style question — describe the trend
Using the table, describe how the volume of carbon offsetting changed between 2010 and 2021. [2]
Model answer
- Overall trend + figures: offsetting rose overall, from about 40 Mt CO₂e in 2010 to about 160 Mt in 2021 — roughly a fourfold increase.
- Add detail: the rise was slow up to 2016 (40 → 60 Mt) then much faster after 2016.
Final answer
1 mark for the overall trend (an increase) + 1 mark for valid quantification (e.g. 40 → 160 Mt, or the post-2016 acceleration).
Markband marks: (1) Argue both sides (one-sided answers cap mid-band). (2) Anchor each side to a named example. (3) End on an explicit judgement that answers 'to what extent'.