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Chemistry · Paper 2 · Foundation + Higher · C9

Human activities and greenhouse gases

Key ideas1 of 3

Why carbon dioxide increases

Burning fossil fuels transfers stored carbon into atmospheric carbon dioxide. Deforestation means fewer trees remove carbon dioxide by photosynthesis. Burning or decaying felled trees can also release their stored carbon.

Burning fossil fuels releases carbon dioxide. Deforestation reduces uptake by photosynthesis; burning and decay can release stored carbon.

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Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · C9. All C9 lessons are shared by Foundation and Higher Tier.

AQA Combined Science Trilogy 8464 · 5.9.2.2. Original notes, questions and diagrams. Models are simplified; illustrative data are labelled.