# Acid rain is a form of air pollution caused by the release of sulfur dioxide from the burning of fossil fuels. Explain how the burning of fossil fuels contributes to air pollution and describe two harmful effects that acid rain can have on ecosystems.

> Cambridge International IGCSE Biology (0610) — 20.3 Pollution · Explain · 4 marks

> Fossil fuels such as coal and oil are burned in power stations and vehicles, releasing pollutant gases into the atmosphere. One of these pollutants, sulfur dioxide, dissolves in water vapour in the atmosphere to form acid rain.

## Mark scheme (4 marks)

1. Burning fossil fuels releases sulfur dioxide (and/or carbon dioxide) into the atmosphere, causing air pollution
2. Acid rain lowers the pH of soil, making it less fertile / preventing plant growth
3. Acid rain lowers the pH of lakes and rivers, killing aquatic organisms
4. Loss of organisms from affected habitats disrupts food chains / reduces biodiversity

## Key terms

- [fossil fuel](https://www.gradenine.co.uk/glossary/fossil-fuel)
- [pollution](https://www.gradenine.co.uk/glossary/pollution)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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/acid-rain-is-a-form-of-e58b2b53) · Published by Druglandscape Ltd.