Increased gas (greenhouse) carbon dioxide, methane, and nitrous oxide, CFC.

This is a natural warming process of the earth where the earth’s atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun’s energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth’s surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth’s surface and atmosphere.

This is a natural warming process of the earth where the earth's atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun's energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth's surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth's surface and atmosphere.