IGCSE Biology glossary
Greenhouse effect
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
The natural process by which certain gases in the Earth's atmosphere (greenhouse gases such as carbon dioxide, methane and water vapour) trap heat energy radiated from the Earth's surface, keeping the planet warm enough to support life. The enhanced greenhouse effect caused by increased greenhouse gas emissions leads to global warming.
What to include in an exam answer
Distinguish between the natural greenhouse effect (necessary for life) and the enhanced greenhouse effect (caused by human activities). In exam answers, explain the mechanism: greenhouse gases absorb and re-radiate infrared radiation.
Example in context
Describe how increased carbon dioxide levels contribute to global warming (3 marks): Carbon dioxide is a greenhouse gas. It absorbs infrared (heat) radiation that is re-emitted from the Earth's surface. The heat energy is re-radiated back towards the Earth, causing the atmosphere to warm up.
Related syllabus topic
Human influences on ecosystems