# Describe how human activities contribute to the greenhouse effect and explain why this is a cause for concern.

> WJEC A-Level Biology (Wales) — 3.6 Human impact on the environment · Describe · 5 marks

> The concentration of carbon dioxide in the atmosphere has increased significantly since the industrial revolution. Scientists link this rise to human activities and warn of serious consequences for the planet.

## Mark scheme (5 marks)

1. Burning fossil fuels releases carbon dioxide into the atmosphere
2. Deforestation reduces the removal of carbon dioxide by photosynthesis / fewer trees to absorb CO2
3. Greenhouse gases (such as carbon dioxide and methane) trap heat / infrared radiation in the atmosphere
4. This leads to global warming / an increase in average global temperatures
5. Global warming causes a named consequence, e.g. rising sea levels due to melting ice caps / glaciers, more extreme weather events, loss of habitats / species extinction, changes to ecosystems

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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-how-human-activities-contribute-to-95295ffd) · Published by Druglandscape Ltd.