Permafrost and biological methane : two carbon time-bombs

 

For the first time since records began, the parts per million (ppm) of CO2 in the atmosphere were over 400 in March 2015.

CO2 threat level

For 400 000 years, carbon dioxide concentrations have remained steady at a level beneath 280 ppm. In the 1980’s a major change occurred, carbon dioxide concentrations rose more than 120ppm since pre-industrial times. In 1988, we reached a first significant milestone with a global average of 350ppm which is considered as the last “safe” level of carbon dioxide in the atmosphere.

450ppm is the tipping point to an era with temperatures above 2C which is a critical threshold. Surpassing this level means a high level of uncertainty in with climate changes that might not be controlled or anticipated anymore.

 

On behalf of permafrost

Often referred as the “terrible child”, carbon dioxide is not the only one responsible for the climate change.

Indeed, methane is 28 times more potent as heat-trapping gas as carbon dioxide is. The problem is : methane is everywhere. Farming, agriculture, human activities, they all produce it and even worse: methane emissions are stored in the sea-ice.

 

The thing is, the more CO2 levels increase, the more temperatures increase. The more temperatures increase, the more methane escapes from the ice, contributing to a rise of temperatures. This “climate feedback loop” is even more dangerous because it is not yet fully understood.

That is why the thawing of permafrost in Siberia, Canada and the Arctic region, which is an ongoing project, is a real climate time-bomb.

 

Biological methane and Arctic lakes

New researches into the changing ecology of thousands of shallow lakes on the North slopes of Alaska suggest that in scenarios of increasing global temperatures, methane-generating microbes, found in thawing lake sediments, may ramp up production of the potent greenhouse gas.

A study published this month in Geobiology, resulting from five years of collaborative research illustrates how the decomposition of organic matter can produce up to three times more biological methane gas emissions when subjected to increased temperatures in a simulated environment.

“In scenarios of warming climate” the author of the study said, “our measurements indicate that biological methane production may play a larger role in the total of methane emissions in the future, which could have a significant impact on our climate”.