Key Stage 3 (KS3) Geography Practice Test

Greenhouse gases are defined as gases in Earth's atmosphere that trap heat. They function within the atmosphere to absorb and re-radiate infrared radiation, which helps maintain the planet's temperature and supports life. This process is known as the greenhouse effect. Key greenhouse gases include carbon dioxide, methane, and nitrous oxide, among others. Understanding that these gases are essential for regulating the Earth's climate helps clarify their importance. If there were no greenhouse gases, the Earth's surface would be significantly colder, making it less hospitable for living organisms. In contrast, while some gases can contribute to air pollution, not all greenhouse gases are pollutants, and their primary function is to maintain warmth in the atmosphere rather than directly cool the Earth's surface or be associated with volcanic activities.