If Paris Agreement Were Working, Methane Levels Would Be Falling; They're Rising Faster Than Ever

[hatrack]

If the world were on track to meet the Paris Agreement goal of less than 2 degrees Celsius of global warming, methane levels in the atmosphere would theoretically be dropping. Instead, they have been rising since 2007, and shooting up even faster since 2014. A perspective published in the journal Science discusses the potential causes and consequences of our planet's out-of-control methane.

Methane decays in the atmosphere faster than carbon dioxide does, but it is a far more powerful greenhouse gas. According to the U.S. Environmental Protection Agency, a molecule of methane will cause 28-36 times more warming than a molecule of carbon dioxide over a 100-year period. Recent data shows that methane concentrations in the atmosphere have risen from about 1,775 parts per billion in 2006 to 1,850 parts per billion in 2017.

The emissions targets in the Paris Agreement were based largely on data from the 1990s and early 2000s, when methane levels were flatter, said Sara Mikaloff Fletcher, a climate scientist with New Zealand's National Institute of Water and Atmospheric Research in Wellington and first author of the new article. The only emissions scenario that achieves Paris Agreement goals in climate models assumes that methane levels have been declining since 2010, when in fact they have been rising since 2007, she said. There may be other ways of keeping climate change under 2 degrees Celsius, but they would involve compensating for rising methane with more drastic cuts to other greenhouse gases.

Scientists aren't sure why methane levels are rising. A 2017 study attributes about half of the increase to cows and other ruminant livestock, which burp methane as they digest food. Another contributing factor could be that people are releasing more fossil fuel emissions while burning less wood and other biomass.

EDIT

https://phys.org/news/2019-06-methane-thwart-efforts-catastrophic-climate.html

[muriel_volestrangler]

1. Methane released during fracking?

It seems highly likely to me that once you start fracturing rocks underground that contain the gas, the methane won't all just flow to your desired collection point, but find other ways to the surface.

[zipplewrath]

2. Thawing Permafrost

Rising temperatures could be triggering wetlands to release more methane, and changes in atmospheric chemistry could be slowing the rate at which methane breaks down.

There's been some evidence that the melting glaciers, and melting permafrost are causing the release of otherwise "captured" methane and CO2. Some of the Climate scientists have already opined that we may be past the point of no return. I suspect they are correct.

[Calculating]

3. Exactly

We've probably hit one of those positive feedback loops that we were warned about. Things are beginning to slip out of our control at this point.

[Boomer]

5. This. n/t

[progree]

4. The equivalent of 59 ppm of CO2, on top of the 415 ppm of actual CO2 we already have

(415 ppm CO2 is the May 2019 average)

According to the U.S. Environmental Protection Agency, a molecule of methane will cause 28-36 times more warming than a molecule of carbon dioxide over a 100-year period. Recent data shows that methane concentrations in the atmosphere have risen from about 1,775 parts per billion in 2006 to 1,850 parts per billion in 2017.

Picking 32 times more powerful than CO2 -- midway between 28 and 36

1850 ppb methane * 32 = equivalent of 59 ppm of CO2

(yes, I know the 1850 ppb methane figure is from 2017, being compared to a 2019 number for CO2. Am too lazy to project a 2019 number for methane. I just wanted an idea of the climate heating magnitude of this)