Rob Jackson, a Stanford researcher and co-author of both studies, said: “Perhaps we can’t do anything that will have a greater impact than shaving methane in shaping the maximum temperature over the next few decades.”
Methane is relatively low: Carbon dioxide is about 200 times more concentrated in the atmosphere. Nevertheless, according to a recent report by the UN Intergovernmental Panel on Climate Change, it has contributed about 30% or about 0.5 ˚C to global warming to date. Although its lifespan in the atmosphere is only 10 years, in a short period of time it is a greenhouse gas about 86 times more powerful than carbon dioxide.
“Methane is going to go away, but in the meantime it will cause problems,” said Vaishali Naik, an atmospheric scientist at the US National Oceanic and Atmospheric Administration.
Due to its short lifespan, if methane emissions are reduced today, atmospheric levels will decrease rapidly. In a recent report by the United Nations Environment Program on methane, which Naik co-authored, researchers estimated that reducing methane emissions by 45% could reduce global warming by 0.28 degrees Celsius in the Middle Ages – setting the world at a pre-industrial level of 1.5 degrees Celsius.
About two-thirds of the cut can be achieved using readily available solutions, Naik says. These include plugging out leaking natural-gas wells and reducing reliance on coal mining, which is the free methane that accumulates beneath the earth’s surface and is produced when plant matter is converted to coal. He said cutting some emissions is probably cheaper and easier than increasing removal technology.
But to keep temperatures below 1.5 degrees Celsius, methane emissions from industries such as agriculture also need to be reduced – which can be difficult with population growth.