evidence: ‘Greenhouse gases’ are crucial to keeping our planet at a suitable temperature for life. Without the natural greenhouse effect, the heat emitted by the Earth would simply pass outwards from the Earth’s surface into space and the Earth would have an average temperature of about -20°C. A greenhouse gas is called that because it absorbs infrared radiation from the Sun in the form of heat, which is circulated in the atmosphere and eventually lost to space. Greenhouse gases also increase the rate at which the atmosphere can absorb short-wave radiation from the Sun, but this has a much weaker effect on global temperatures. [...] Footnotes 1. Enhanced Greenhouse effect 'Greenhouse gases' are actually crucial to keeping our planet at a habitable temperature, without them the Earth would be about minus 17 degrees! Anthropogenic or human release of carbon dioxide is what is contributing to an additional or enhanced greenhouse effect.