Shrinking Arctic glaciers reveal source of methane that could accelerate global warming, warn University of Cambridge and Svalbard researchers

Shrinking glaciers are exposing groundwater springs which could provide an underestimated source of the potent greenhouse gas methane as the Arctic warms, researchers have found.

A study, led by researchers from the University of Cambridge and the University Centre in Svalbard, Norway, identified large stocks of methane gas leaking from groundwater springs unveiled by melting glaciers.

It suggests that these methane emissions will likely increase as Arctic glaciers retreat and more springs are exposed. This, and other methane emissions from melting ice and frozen ground in the Arctic, could exacerbate global warming.

Gabrielle Kleber, lead author of the research who is from Cambridge’s Department of Earth Sciences, said: “These springs are a considerable, and potentially growing, source of methane emissions – one that has been missing from our estimations of the global methane budget until now.”

Scientists are concerned that additional methane emissions could ramp up human-induced global warming. The springs the researchers studied had not previously been recognised as a potential source of methane emissions.

The researchers found methane emissions from glacial groundwater springs across Svalbard could exceed 2,000 tonnes in a year, which is roughly 10 per cent of the methane emissions resulting from Norway’s annual oil and gas energy industry.

Prof Andrew Hodson, study co-author from the University Centre in Svalbard said, “Living in Svalbard exposes you to the frontline of Arctic climate change. I can’t think of anything more stark than the sight of methane outgassing in the immediate forefield of a retreating glacier.

“The amount of methane leaking from the springs we measured will likely be dwarfed by the total volume of trapped gas lying below these glaciers, waiting to escape.

“That means we urgently need to establish the risk of a sudden increase in methane leakage because glaciers will only continue to retreat while we struggle to curb climate change.”

The research was published last Thursday (July 6) in Nature Geoscience.