The Arctic’s carbon bomb might be even more potent than we thought

https://www.washingtonpost.com/news/energy-environment/wp/2018/03/19/the-arctics-carbon-bomb-might-be-even-more-potent-than-we-thought/?nid&utm_term=.96945f06d58e

By Chris Mooney March 19, 2018

For some time, scientists fearing the mass release of greenhouse gases from the carbon-rich, frozen soils of the Arctic have had at least one morsel of good news in their forecasts: They predicted most of the gas released would be carbon dioxide, which, though a greenhouse gas, drives warming more slowly than some other gases. Scientists obviously weren’t excited about more carbon dioxide emissions, but it was better than the alternative: methane, a shorter-lived but far harder-hitting gas that could cause faster bursts of warming.

Now even that silver lining is in doubt.

Research released Monday suggests that methane releases could be considerably more prevalent as Arctic permafrost thaws. The research finds that in waterlogged wetland soils, where oxygen is not prevalent, tiny microorganisms will produce a considerable volume of methane, a gas that doesn’t last in the air much more than a decade but has a warming effect many times that of carbon dioxide over a period of 100 years.

“What we can definitely say is that the importance of methane was underestimated until now in the carbon studies,” said Christian Knobloch, a researcher at Universität Hamburg in Germany and the lead author of the study, published in Nature Climate Change.

The divergent finding came after Knoblauch and his colleagues conducted a lengthy experiment, more than seven years long, monitoring patches of submerged and artificially warmed soil from Siberia in the laboratory, and gradually seeing sensitive methane-producing microorganisms become more prevalent over time.

Knoblauch contends that other studies have not examined waterlogged Arctic soils for as long, and he notes that in some cases it took three years or more for the methane-generating microorganisms to really get cranking.

“What we saw is that it takes a very long time until methane starts being produced, and the study that we did is really the first one which is so long,” Knoblauch said.

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