SOURCE: The Guardian
DATE: February 17, 2019
SNIP: Dramatic rises in atmospheric methane are threatening to derail plans to hold global temperature rises to 2C, scientists have warned.
In a paper published this month by the American Geophysical Union, researchers say sharp rises in levels of methane – which is a powerful greenhouse gas – have strengthened over the past four years. Urgent action is now required to halt further increases in methane in the atmosphere, to avoid triggering enhanced global warming and temperature rises well beyond 2C.
“What we are now witnessing is extremely worrying,” said one of the paper’s lead authors, Professor Euan Nisbet of Royal Holloway, University of London. “It is particularly alarming because we are still not sure why atmospheric methane levels are rising across the planet.” [Ed note: Perhaps these guys need to get together with these guys.]
During much of the 20th century, levels of methane, mostly from fossil fuel sources, increased in the atmosphere but, by the beginning of the 21st century, it had stabilised, said Nisbet. “Then, to our surprise, levels starting rising in 2007. That increase began to accelerate after 2014 and fast growth has continued.”
Studies suggest these increases are more likely to be mainly biological in origin. However, the exact cause remains unclear. Some researchers believe the spread of intense farming in Africa may be involved, in particular in tropical regions where conditions are becoming warmer and wetter because of climate change.
However, other scientists warn that there could be a more sinister factor at work. Natural chemicals in the atmosphere – which help to break down methane – may be changing because of temperature rises, causing it to lose its ability to deal with the gas.
Our world could therefore be losing its power to cleanse pollutants because it is heating up, a climate feedback in which warming allows more greenhouse gases to linger in the atmosphere and so trigger even more warming.