Arctic tundra is 80 per cent permafrost. What happens when it thaws?

Arctic tundra is 80 per cent permafrost. What happens when it thaws?

SOURCE: The Narwhal DATE: March 11, 2020 SNIP: The tundra of the western Canadian Arctic has long been carpeted in cranberries, blueberries, cloudberries, shrubs, sedges, and lichen that have provided abundant food for grizzly bears, caribou, and other animals. Now, however, as permafrost thaws and slumping expands, parts of that landscape are being transformed into nothing but mud, silt, and peat, blowing off massive amounts of climate-warming carbon that have been stored in the permafrost for millennia. What we do know is that if the Arctic continues to warm as quickly as climatologists are predicting, an estimated 2.5 million square miles of permafrost — 40 per cent of the world’s total — could disappear by the end of the century, with enormous consequences. The most alarming is expected to be the release of huge stores of greenhouse gases, including methane, carbon dioxide, and nitrous oxide that have remained locked in the permafrost for ages. Pathogens will also be released. But less well appreciated are the sweeping landscape changes that will alter tundra ecosystems, making it increasingly difficult for subsistence Indigenous people, such as the Inuit, and Arctic animals to find food. The disintegration of subterranean ice that glues together the peat, clay, rocks, sand, and other inorganic minerals is now triggering landslides and slumping at alarming rates, resulting in stream flows changing, lakes suddenly draining, seashores collapsing, and water chemistry being altered in ways that could be deleterious to both humans and wildlife. “We’re seeing slumping along shorelines that can drain most of the water in a lake in just days and even hours,” says Canadian scientist Philip Marsh,...
Rapid Permafrost Collapse Is Underway, Disintegrating Landscapes And Our Predictions

Rapid Permafrost Collapse Is Underway, Disintegrating Landscapes And Our Predictions

SOURCE: Science Alert and Nature Geoscience DATE: February 5, 2020 SNIP: Permafrost in Canada, Alaska and Siberia is abruptly crumbling in ways that could release large stores of greenhouse gases more quickly than anticipated, researchers have warned. Scientists have long fretted that climate change – which has heated Arctic and subarctic regions at double the global rate – will release planet-warming CO2 and methane that has remained safely locked inside Earth’s frozen landscapes for millennia. It was assumed this process would be gradual, leaving humanity time to draw down carbon emissions enough to prevent permafrost thaw from tipping into a self-perpetuating vicious circle of ice melt and global warming. But a study published on Monday in Nature Geoscience says projections of how much carbon would be released by this kind of slow-and-steady thawing overlook a less well-known process whereby certain types of icy terrain disintegrate suddenly – sometimes within days. “Although abrupt permafrost thawing will occur in less than 20 percent of frozen land, it increases permafrost carbon release projections by about 50 percent,” said lead author Merritt Turetsky, head of the Institute of Arctic and Alpine Research in Boulder, Colorado. “Under all future warming scenarios, abrupt thaw leads to net carbon losses into the atmosphere,” she told AFP. Current climate models do not account for the possibility of rapid permafrost collapse and the amount of gases it might release, the study notes. Abrupt thawing is “fast and dramatic”, Merritt said, adding: “Forests can become lakes in the course of a month, landslides can occur with no warning, and invisible methane seep holes can swallow snowmobiles...
The Arctic’s grand reveal

The Arctic’s grand reveal

SOURCE: University of Alaska Fairbanks DATE: December 12, 2019 SNIP: “This green line looks like the death of permafrost — it’s flatlining,” Louise Farquharson said to an audience of a few dozen scientists. Her reserved tone hid a bombshell message — by 2035 permafrost thaw may continue on its own, disregarding the processes that have kept it frozen for thousands of years. Farquharson is a research associate at the University of Alaska Fairbanks Geophysical Institute. She is an expert on permafrost, the parts of the ground that stay frozen for at least two consecutive years. Permafrost thaw causes the ground surface to sink, which leads to infrastructure damage, accelerates microbial activity and releases carbon and other gases into the atmosphere, accelerating global warming even more. Most experts suggest permafrost thaw will continue and even speed up as we go into the next century. However, calculated rates of thaw may be far lower than what will really happen. According to Farquharson, a key accelerating factor in permafrost thaw has been dramatically underestimated. “It’s the Arctic’s ‘grand reveal,’” Farquarson said. “We thought we saw what was happening, then it really stepped out from behind the curtain.” This factor is called talik, thawed zones in permafrost areas. The mixture of wet, frigid dirt is commonly associated with Arctic thermokarst lakes that form when enough ice-rich permafrost thaws to create a body of water. The talik beneath these lakes significantly contributes to the thawing process. Just as icewater melts faster than a lone cube of ice, the waterlogged ground accelerates thawing of the permafrost around it. Normally talik has been thought of as...
The Arctic may have crossed key threshold, emitting billions of tons of carbon into the air, in a long-dreaded climate feedback

The Arctic may have crossed key threshold, emitting billions of tons of carbon into the air, in a long-dreaded climate feedback

SOURCE: Washington Post DATE: December 10, 2019 SNIP: The Arctic is undergoing a profound, rapid and unmitigated shift into a new climate state, one that is greener, features far less ice and emits greenhouse gas emissions from melting permafrost, according to a major new federal assessment of the region released Tuesday. The consequences of these climate shifts will be felt far outside the Arctic in the form of altered weather patterns, increased greenhouse gas emissions and rising sea levels from the melting Greenland ice sheet and mountain glaciers. The findings are contained in the 2019 Arctic Report Card, a major federal assessment of climate change trends and impacts throughout the region. The study paints an ominous picture of a region lurching to an entirely new and unfamiliar environment. Especially noteworthy is the report’s conclusion that the Arctic already may have become a net emitter of planet-warming carbon emissions due to thawing permafrost, which would only accelerate global warming. Permafrost is the carbon-rich frozen soil that covers 24 percent of the Northern Hemisphere’s land mass, encompassing vast stretches of territory across Alaska, Canada, Siberia and Greenland. There has been concern throughout the scientific community that the approximately 1,460 billion to 1,600 billion metric tons of organic carbon stored in frozen Arctic soils, almost twice the amount of greenhouse gases as what is contained in the atmosphere, could be released as the permafrost melts. [T]he report concludes permafrost ecosystems could be releasing as much as 1.1 billion to 2.2 billion tons of carbon dioxide per year. This is almost as much as the annual emissions of Japan and Russia in 2018,...
Abrupt shifts in Arctic climate projected

Abrupt shifts in Arctic climate projected

SOURCE: McGill University and Nature Climate Change DATE: October 30, 2019 SNIP: Researchers from McGill University project that as the permafrost continues to degrade, the climate in various regions of the Arctic could potentially change abruptly, in the relatively near future. Their research, which was published today in Nature Climate Change, also suggests that as the permafrost degrades, the severity of wildfires will double from one year to the next and remain at the new and higher rate for regions in the Northwestern Territories and the Yukon. Prior research in the field has tended to project a gradual degradation of the permafrost, with few direct effects on climate. Typically, researchers will model climate changes by looking backwards and forwards in 20-30 year blocks, making it easier to miss the abrupt changes that are taking place. The McGill researchers analyzed the effects of changes in the permafrost on a completely different level. “There’s not much high-resolution climate modelling done of the Arctic. Our initial climate model experiments at 50km resolution allowed us to extract critical information on climate shifts” says Bernardo Teufel, the first author on the paper, who is currently working on his PhD research at McGill. “We used climate model data spanning the 1970-2100 period to understand probable changes in the Arctic climate and permafrost. What we came away with, was a picture of alarming changes to climate driven by permafrost...