Solar radiation global warming, illustration. Radiation energy from the Sun enters the Earth's atmosphere. The Earth's surface absorbs some radiation, reflects some, and re-radiates some as infrared radiation (heat). Some of this radiation passes through the atmosphere back into space, but the build-up of certain chemicals in the atmosphere can change its absorbance and emission of radiation. Carbon dioxide, which is produced by the burning of fossil fuels, is a major greenhouse gas. It absorbs the radiation and re-emits it, contributing to global warming.