# Explain why it is difficult for scientists to predict the effects of increased greenhouse gas emissions on global climate change.

> AQA GCSE Chemistry (8462) — 4.9.3 Common atmospheric pollutants and their sources · Explain · 4 marks

> Many scientists use computer models to predict how increasing levels of carbon dioxide and methane in the atmosphere will affect the Earth's climate. However, there is debate about the reliability of these predictions.

## Mark scheme (4 marks)

1. Global climate is a very complex system (so it is difficult to model accurately)
2. Models have to be simplified / models may only use part of the evidence
3. This leads to speculation and opinions that may be biased
4. Predictions are based on peer-reviewed evidence but uncertainty remains / scientists believe (not certain) human activities cause temperature increase

## Key terms

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

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](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-why-it-is-difficult-for-32f0aa20) · Published by Druglandscape Ltd.