# Describe the natural greenhouse effect and explain why an increase in the concentration of greenhouse gases in the atmosphere leads to climate change.

> Pearson Edexcel International GCSE Chemistry (4CH1) — 2.3 Gases in the atmosphere · Describe and Explain · 4 marks

> Greenhouse gases such as water vapour, carbon dioxide and methane are naturally present in the Earth's atmosphere. Human activities, including the burning of fossil fuels, have increased the concentration of these gases over the past two centuries.

## Mark scheme (4 marks)

1. Greenhouse gases trap/absorb infra-red radiation (from the Earth's surface)
2. This keeps/raises the temperature of the Earth's atmosphere, making it warm enough to support life
3. An increased concentration of greenhouse gases means more infra-red radiation is trapped/absorbed
4. This causes a rise in global temperatures / leads to climate change

## Key terms

- [greenhouse effect](https://www.gradenine.co.uk/glossary/greenhouse-effect)
- [greenhouse gases](https://www.gradenine.co.uk/glossary/greenhouse-gases)
- [climate change](https://www.gradenine.co.uk/glossary/climate-change)

## Related

- [Revision notes for Pearson Edexcel International GCSE Chemistry (4CH1)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and 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/describe-the-natural-greenhouse-effect-and-d4990611) · Published by Druglandscape Ltd.