Siberia, one of the world's largest storehouses of frozen greenhouse gases, is melting at a quickened pace.
Over the last 7,000 years, winter temperatures in the Siberian permafrost regions have gradually risen, according to new research from German and Russian scientists at the Alfred Wegener Institute (AWI) and published in the journal Nature Geoscience. It's a trend that has long been predicted by climate models but never before been proved.
Using 42 samples from 13 ice wedges from the Lena River Delta area of Russia, the researchers were able to use oxygen isotope analysis to analyze temperature data stored in the ice and reconstruct the climate curve in that area.
In the past, researchers have primarily used fossilized pollen and tree rings from the Arctic, but they only record climate data from the summertime when plants grow and bloom. Ice wedges, on the other hand, are archives of the long Siberian winters.
"We show that the winters have been moderately warming in the last 7,000 years by natural reasons, plus an accelerated warming in the last decades, very likely caused by enhanced greenhouse gas emissions," said lead author of the study Hanno Meyer, a permafrost researcher at AWI.
Long-term winter warming is to be expected, Meyer said, because of the way the Earth and sun's orbital pattern changes over time; however, since about 1850, the researcher's data shows a spike in temperatures.
Thawing permafrost all over the Arctic has been on scientists' radar for a while, and it has serious ecological and economic implications for the Siberian region and beyond it.
In November 2012, the U.N. Environment Programme released a report that found the thawing of vast areas of permafrost in Russia, Canada and the United States would not only release large stores of carbon but would threaten infrastructure like roads, railways and oil pipelines.
Massive storehouse of carbon dioxide
Permafrost is a layer of rock, sediment or other organic material that remains frozen for at least two consecutive years. Often, if the permafrost is not covered by a layer of ice, it will lie below a layer of "active permafrost" rock, soil or sediment, which freezes and thaws annually.
Permafrost is also an enormous storehouse of carbon dioxide and methane. It's estimated that 24 percent of the land in the Northern Hemisphere is permafrost and sequesters a third of the world's soil. By 2200, 60 percent of the Northern Hemisphere's permafrost will probably be melted, which could release around 190 billion tons of carbon dioxide into the atmosphere, according to estimates by researchers at the National Snow and Ice Data Center.
"Permafrost is a key element," said Nikolay Shiklomanov, an associate professor in the Department of Geography at George Washington University and an Arctic researcher. "Everybody's talking about the glaciers melting, and they're spectacular, but the glaciers only occupy 10 percent of the Northern Hemisphere, and permafrost is a quarter. It's not as spectacular, but it's extremely important for everything."
Winter warming could impact the length of time the active layer is frozen, as well as its depth, and the amount of snow covering permafrost. As permafrost thaws, the physical topography of an area can shift, Meyer said.
Winners and losers in Russia's economy
Permafrost accounts for about half of all of Russia's land area. Five percent of Russia's population lives on it, and about 11 percent of Russia's gross domestic product comes from Arctic land, mainly through oil, gas and mineral mining extractions.
"From a Russian perspective, there will be winners and losers from climate change," said Oleg Anisimov, a professor of physical geography at the Hydrological Institute in St. Petersburg and one of Russia's leading experts on the impacts of climate change on the environment. "Warmer winters will mean permafrost regions will be more livable and require less resources for heating homes."
On the other hand, Anisimov said, thawing permafrost will affect oil and gas pipeline infrastructure, railways, roads and foundations of houses. As permafrost thaws, depending on the amount of ice contained in the vegetation, the ground shifts, sometimes dramatically destroying buildings and roads.
Higher temperatures could also increase the growing season in the Arctic, which would be good for local agriculture, traditionally a staple for the Russian people, especially the 4 million living in the Arctic.
But it's really a Catch-22. Much of the reason for families to settle in permafrost-rich regions of the Siberian Arctic is because of the oil, gas and minerals industry. Thawing permafrost actually reduces the ability of those industries to extract resources.
"In Russia, in big Russian communities, they are pretty much isolated, cities of like 70,000, they can only get supplies by rail and sea routes," Shiklomanov said. "If seasons are longer, that might help, but on the other hand, if you look at what makes those cities where they are, it is natural resources. The ability to explore those things is getting harder. You can only drive big rigs on solid permafrost."
The only feasible way to mitigate warming in the Arctic is to reduce greenhouse gas emissions, said Anisimov, and from a Russian perspective, not all aspects of climate change harm those living in the Siberian regions.
"If the international world doesn't have something in place [to curb emissions], why should we sacrifice if this is going to be good for us?" he said.
Regardless, permafrost is an important feedback mechanism for climate change in the arctic, and this new research provides empirical proof for the winter warming phenomenon that scientists believed was happening, Shiklomanov said.
"It's just one region, but every region is significant in the Arctic," he said.