Telegraph: Energy from the sun arrives as visible and ultraviolet light, which is absorbed by the Earth. Some of this energy is released from Earth again as heat. Greenhouse gases in the atmosphere trap this heat and bounce it back towards the Earth's surface.
Laboratory experiments show that carbon dioxide can absorb and then emit heat, while satellite observations reveal that the amount of heat being released into the atmosphere is changing.
Some greenhouse gases, such as methane and nitrous oxide,...