I'm sure you won't be unfamiliar with the name methane. Methane consists of one carbon and four hydrogen atoms. Its chemical formula is CH4. Although its appearance is very "simple", its ability is not simple at all. Methane is the main component of natural gas, biogas, oil field gas and mine pit gas. It can also be used as fuel and raw material to produce hydrogen, carbon monoxide, hydrocyanic acid and formaldehyde. Therefore, methane is widely used as fuel and raw material in civil and industrial applications.

The sources of atmospheric methane include ecosystem and human activities, among which natural sources include natural wetland, vegetation, ocean and methane hydrate; human sources include energy activities (coal mining and oil and gas system), agricultural activities (ruminant, paddy field discharge and straw burning in the open air), waste treatment (solid waste, industrial sewage and domestic sewage) and artificial wetland. Permafrost and ice in the Arctic hold a lot of methane. These methane gases are hidden under the ice, just like the "ice grenade" waiting to be detonated. If the ice is punctured to let the methane gas overflow upward, you can use matches to ignite and form a huge ice "flame" or even an explosion. Biogas hidden under the Arctic ice has also been suspected to be a great threat to global warming. Some researchers think that as the Arctic ice thins, the biogas in the Arctic frozen soil and sea water sediment becomes more active, which is very easy to leak into the atmosphere.

Methane can not only provide heat as fuel, but also an important greenhouse gas next to carbon dioxide, which can save heat for the earth. According to the fifth IPCC Assessment Report, the global warming potential (GWP) of methane is 28 times that of carbon dioxide in 100 years, and its residence time in the atmosphere is about 9.1 years. Since the industrial era, the concentration of atmospheric methane has increased from 722ppb in 1750 to 1840ppb in 2015, which is more than 155% of the pre industrial level, and is still growing. The IPCC report points out that the increase of ruminant population, the extraction and application of fossil fuels, the expansion of agricultural rice, and the increase of landfill are the main reasons for the increase of atmospheric methane concentration. At the same time, the report considers that anthropogenic emissions account for 50% - 65% of the global total.

Global warming is a common challenge for all mankind. On February 9, Brazilian scientists recorded a high temperature of 20.75 ℃ on the island of Seymour, Antarctica, nearly 1 ℃ higher than the 19.8 ℃ recorded by the island in 1982. Then there was news on the other side of the globe - on February 14, a NASA study found two million methane emission hotspots in 300000 square kilometers of the Arctic. To slow down global warming, controlling greenhouse gas emissions is the top priority. Methane as an important greenhouse gas, if we don't pay attention to it, we will have to face the problem of global warming caused by the massive release of methane in the future.