Before 1820, no one had asked how the earth obtained heat. It was in that year that Jean-Baptiste-Joseph Fourier (1768-1830, French mathematician and Egyptologist), after returning to France, he wore a coat all year Most of the time is spent on heat transfer research. He concluded that although the earth did reflect a lot of heat back into space, the atmosphere still blocked some of it and reflected it back to the surface of the earth. He likened this to a huge bell-shaped container with clouds and gas at its top, capable of retaining enough heat to make life possible. His paper "Overview of the Temperature of the Earth and Its Surface Space" was published in 1824. At that time, this paper was not regarded as his best work, and it was not remembered again until the end of the 19th century.
In fact, it is only because the infrared rays of the earth are absorbed by certain gases or compounds in the atmosphere around the earth during the process of radiation to space that eventually lead to a general rise in global temperature. Therefore, the functions of these gases are similar to those of greenhouse glass, and only the sun is allowed. Light enters, and prevents its reflection, and then achieves the effect of heat preservation and heating, so it is called greenhouse gas. These include not only the various oxides of water vapor, carbon dioxide, and nitrogen that existed in the atmosphere, but also the hydrofluorocarbons (HFCs), hydrofluorides, perfluorides (PFCs), Sulfur fluoride (SF6), chlorofluoride (CFCs), etc. The heat absorption capacity of different types is also different. The heat absorption per molecule of methane is 21 times that of carbon dioxide, and nitrogen oxides are higher, which is 270 times that of carbon dioxide. However, it is nothing compared to some man-made greenhouse gases. The strongest heat absorption capacity is hydrofluorocarbons (HFCs) and perfluorinated compounds (PFCs).