# Explain how methane and carbon dioxide act as greenhouse gases to cause global warming.

> Pearson Edexcel International GCSE Biology (4BI1) — 4.4 Human influences on the environment · Explain · 4 marks

> Cattle farming and the burning of fossil fuels release large quantities of methane and carbon dioxide into the atmosphere. Scientists have recorded a steady rise in average global temperatures over the past century.

## Mark scheme (4 marks)

1. Methane and carbon dioxide are greenhouse gases that trap heat (thermal/infrared radiation) in the Earth's atmosphere
2. As levels of carbon dioxide and methane in the atmosphere increase, more heat is trapped
3. This leads to a gradual rise in the average temperature of the Earth (global warming)
4. Named consequence of global warming — e.g. polar ice caps melt / sea levels rise / more extreme weather events / changes in species distribution

## Key terms

- [greenhouse gases](https://www.gradenine.co.uk/glossary/greenhouse-gases)
- [global warming](https://www.gradenine.co.uk/glossary/global-warming)
- [methane](https://www.gradenine.co.uk/glossary/methane)
- [carbon dioxide](https://www.gradenine.co.uk/glossary/carbon-dioxide)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-methane-and-carbon-dioxide-b27a3a31) · Published by Druglandscape Ltd.