Carbon dioxide

Carbon dioxide (CO₂) is a chemical compound and is acidic. It is a gas at room temperature. It is made of one carbon and two oxygen atoms. People and most animals release carbon dioxide when they breathe out. Also, every time something organic is burnt (or a fire is made), it makes carbon dioxide. Plants use carbon dioxide to make food. This process is called photosynthesis.^[1] The properties of carbon dioxide were studied by the Scottish scientist Joseph Black in the 1750s.

Carbon dioxide is a greenhouse gas.^[2] Greenhouse gases trap heat energy. Greenhouse gases change the climate and weather on our planet, Earth. This is called climate change. Greenhouse gases are a cause of global warming, the rise of Earth surface temperature.

Its concentration in Earth's atmosphere since late in the Precambrian was regulated by photosynthetic organisms and geological phenomena (mainly volcanos).

1. ↑ Fullick, Ann (2011). Edexcel IGCSE Biology Revision Guide. Pearson Education. p. 40. ISBN 9780435046767.
2. ↑ Woolley, Steve (2011). Edexcel IGCSE Physics Revision Guide. Pearson Education. p. 59. ISBN 9780435046736.