Melting Svalbard glaciers offer ominous taste of further warming to come – Inside Climate News

The remote Arctic islands of Svalbard, Norway, the world’s northernmost settlement, have been called a canary in the coal mine of climate change, warming more than twice as fast as other areas in the Arctic and five to seven times faster than the rest of the planet.

Because of this warming, Svalbard is offering climate researchers a preliminary glimpse into what will happen to the rest of the Arctic.

Research published Thursday in Nature Geoscience examines a new source of Arctic methane emissions in Svalbard from groundwater springs sprouting in areas uncovered by retreating glaciers.

As climate change causes more glaciers to melt, it could create a feedback loop, with glacier melt due to warming producing methane, a potent greenhouse gas, producing more warming. As the Arctic warms faster than climate models predict, identifying new sources of carbon emissions can help to better refine these models.

What we found was that these groundwater sources were completely intact or unknown sources of methane in the Arctic, either on Svalbard or most likely via the Arctic, said Gabrielle Kleber, lead author of the study and a graduate student at the University of Cambridge.

Kleber said researchers have known for years that methane seeps from the ocean floor into areas that had glaciers thousands of years ago. But up to this point no one has directly studied methane seepage on land exposed by retreating glaciers, she said.

As glaciers began to retreat over the past century, a gap formed between the end of the glacier and the beginning of the frozen ground, known as permafrost. Groundwater that was previously trapped under the glacial ice then began bubbling out of these gaps and created a spring.

Researchers have been able to identify these groundwater sources in areas recently discovered by Arctic glaciers via satellite. Then, over three winters, the researchers rode snowmobiles to these frozen springs to take water samples. Over the course of two winters, the researchers sampled 123 springs from 78 glaciers.

Logistically it’s a challenge because you leave the city on your snowmobile and then you’re really fully exposed to the arctic elements, Kleber said. We sampled on days when it’s minus 40 degrees and you need to sample liquid water when it’s between 20 and minus 40 degrees.

After analyzing the samples, the researchers found that the concentration of methane in this water was up to 600,000 times higher than the normal concentration in water. Most of that methane then flows into the atmosphere, where it warms up about 80 times more than carbon dioxide over a 20-year period.

It’s just this very gritty picture of climate change, melting these glaciers and then releasing methane, Kleber said.

Wei-Li Hong, an assistant professor of geochemistry at Stockholm University who was not involved in the study, said the data and analysis of underground sources are very compelling. She said researchers have suspected this type of process is happening, but until now, there has been no experimental evidence.

Evidence suggests that much of the methane from Svalbard sources comes from rocks such as shale or coal, which are common in Svalbard and other areas of the Arctic. When these types of rock form when heat breaks down organic matter such as dead plants and animals, the methane becomes trapped in the sediment. Then, as glaciers move over these areas, they create cracks, which allow methane to move back up through the rock. As the glacier retreats, that methane is then released with the help of groundwater.

There is also some evidence that bacteria may also be producing some of this methane through their metabolic process. Hong said further research should examine how glacial retreat affects the methane emissions produced by the bacteria.

While this study focuses only on Svalbard, methane emissions from these types of sources are also likely to occur in other areas of the Arctic. And since Svalbard is warming much faster than other places in the Arctic, it’s also likely that these types of emissions could spread more widely.

This study focuses on glaciers that terminate inland, which account for a small percentage of Arctic glaciers. Glaciers that end up on the water tend to be much larger and account for more glacier area in the Arctic, but as global warming leads to more glacier melt, it’s possible these glaciers are retreating onto land. Of the 1,704 Arctic glaciers that terminate on land, 7% have retreated enough in the past two decades to now be completely on land. Of the inland glaciers studied, nine ended on the ocean in the past century. They have receded enough that they now end up inland and spew methane through underground sources.

Kleber said this system is not currently creating a massive contribution to methane emissions. Svalbard’s methane emissions from this process are approximately 8% of the methane emissions from Norway’s oil and gas emissions.

While these groundwater sources aren’t currently emitting dangerous amounts of methane, scientists estimate that there is about twice as much organic carbon stored under Arctic glaciers and permafrost as there is currently in the atmosphere. The release of methane from these groundwater sources could become more relevant as glaciers continue to shrink in our rapidly warming climate, Kleber said.

The Arctic is currently warming much faster than other places on the planet, and Kleber said it’s warming even faster than climate models predict.

And part of the reason is because there are all these kinds of invisible feedback loops that we weren’t aware of, Kleber said. So we have climate change, the melting of glaciers and the retreat of those glaciers is then releasing methane, which will only exacerbate the warming. So it’s all these hidden links that are just perpetuating climate change that we’re unaware of.