The Arctic is unraveling before our eyes. As our understanding of the changes continues, scientists have been fine-tuning models to give us a sense of how quickly we can expect tipping points to arrive. One of the most terrifying is the permafrost feedback. A new study finds that the feedback just may have arrived. The reason? Winter permafrost carbon emissions are now greater than what can be stored in the summer. To be clear, not all scientists believe that the tipping point has arrived. But regardless, the rapid changes we see in the Arctic, which has warmed 3 times faster than the rest of the earth, are glaringly obvious.
'an influx of permafrost-derived methane into the atmosphere in the mid-21st century, is not currently accounted for in climate projections'
"Within my lifetime…it should be ramping up. It’s already happening… within a few decades, it should peak" 🤯https://t.co/YA5DGD4IJE
— Ben See (@ClimateBen) October 8, 2019
It’s here now, according to research published today by a large team of scientists in Nature Climate Change. By pooling observations from more than 100 Arctic field sites, scientists from the Permafrost Carbon Network estimate that permafrost released an average of 1662 teragrams of carbon each winter from 2003 to 2017—double that of past estimates. Meanwhile, during the summer growing season, other surveys have found that the landscape absorbs only 1032 teragrams—leaving an average of more than 600 teragrams of carbon to escape to the atmosphere each year.
The study remains limited by the paucity of Arctic observations; the overall uncertainty of Arctic winter emissions, for example, is 813 teragrams, nearly half the total emissions. The study also found no rise in emissions since 2003. Still, researchers say, it’s a sign that the permafrost feedback—which would see carbon emissions from permafrost lead to warming that would in turn thaw more permafrost—is already underway.
— APE@GU (@APEGU1) August 21, 2019
Arctic regions have captured and stored carbon for tens of thousands of years, but a new study shows winter carbon emissions from the Arctic may now be putting more carbon into the atmosphere than is taken up by plants each year.
“High-latitude cold regions, including Arctic, are warming more than twice as fast as the rest of the planet, with the greatest warming occurring during the winter. Given that a major process responsible for CO2 emissions; microbial respiration, increases with warming even at sub-zero temperatures, winter is a critical period for carbon cycling,” said study co-author Dr. Fereidoun Rezanezhad, University of Waterloo Water Institute & Ecohydrology Research Group member and professor in Earth and Environmental Sciences.
When #permafrost ice melts, surface soils can collapse abruptly creating depressions. At @ZERO74N a galloping #thermokarst collapsed in 2018 and still keeps changing. Also visible is the cliff face loss at the #Zackenberg River. What a site to observe the #changingArctic pic.twitter.com/DZWzTpFWti
— Greenland Ecosystem Monitoring (@GEM_Arctic) October 15, 2019
Permafrost is the carbon-rich frozen soil that covers 24 percent of Northern Hemisphere land area. Across the globe, from Alaska to Siberia, permafrost holds more carbon than has ever been released by humans. Right now, permafrost keeps carbon safely locked away, but as global temperatures warm, permafrost thaws and releases greenhouse gases to the atmosphere. Carbon from thawing permafrost had been omitted from many models and reports that informed international climate policy.
— Robert H Fraser (@EOArctic) June 15, 2018
Researchers synthesized on-the-ground observations of CO2 emissions to assess current and future winter carbon losses from the northern permafrost regions. They estimate a contemporary loss of 1.7 million metric tons of carbon from the permafrost region during the winter season (October through April). That loss is greater than the average growing season carbon uptake for this region estimated from process models (1.0 million metric tons of carbon taken up per year). Extending model predictions to warmer conditions in 2100 indicates that winter CO2 emissions could increase 17 percent under a moderate mitigation scenario (RCP 4.5) but could rise 41 percent under a business-as-usual emissions scenario (RCP 8.5).
The Helmholtz Center in Potsdam expands on the study here.
The research, published in Nature Communications, showed that wildfires burning across northern peatlands in Alberta and the Northwest Territories triple the rate of abrupt permafrost thaw for up to 30 years after the fire.
Possibly the most discernible carbon-climate feedback: increasing fire activity within the Arctic circle.
Difficult to compute exact emissions but roughly comparable to fossil fuel emissions of countries such as the Netherlands. Potential for much more with ongoing warming. pic.twitter.com/8jryNcV6kI
— Guido van der Werf (@GuidovanderWerf) October 21, 2019
“When the permafrost thaws, the ground goes from being solid to something that is very wet and soupy. It’s exceptionally difficult to move through these thawed areas, and travel across them may be virtually impossible,” she explained.
The effects of wildfire on permafrost in the region included warmer soils, deeper seasonal thaw and an underlying layer of soil that remained unfrozen throughout the entire year.
By assuming peatlands in different parts of the world accumulate peat at different rates, and by weighing those rates by the size of the region, the new algorithm allowed the researchers to calculate that northern peatlands hold 1.1 trillion tons of carbon. That’s a colossal amount of carbon—more than humans have so far dumped to the atmosphere by burning fossil fuels—and quite a jump from the previous estimate of roughly 545 billion tons.
Nichols and Peteet found that after the last glacial period, when the peatlands were absorbing this huge amount of carbon, the level of carbon in the atmosphere remained stable. How could that be, if the peatland plants were pulling carbon out of the air during photosynthesis and then never releasing it? The researchers suspect the ocean released more carbon during that time, which compensated for the carbon removed by the growing peatlands.
Data on permafrost soils can be found here.
How much does wildfire accelerate #permafrost thaw in peatlands? @redflannelphoto took a look and we estimate that wildfire is responsible for about a quarter of all thermokarst bog expansion over the last 30 years in western Canada. New paper @NatureComms https://t.co/kjM7xiFlo0 pic.twitter.com/5kbwNQ94PJ
— David Olefeldt (@DavidOlefeldt) August 2, 2018
The study’s findings also have implications for predicting future carbon emissions from peatlands. “The parts of the world with peat are also the parts that are warming faster than the rest of the world. What happens when you warm them up? Do they grow faster and sequester more carbon, or do they decay faster and release more?” Nichols asks.
In general, he’s finding that peatlands are decaying faster and releasing more carbon as the planet’s thermostat climbs; climate change is disrupting natural rainfall patterns in peatlands, which can push out mosses in favor of plants such as sedges. Sedges grow and decay faster, and their roots bring oxygen deep into the layers of peat, allowing organic material to break down and release carbon that may have been stored there for millennia. In addition, humans often mine peatlands and burn the peat for fuel or use it in agriculture or horticulture. All these processes convert peatlands from absorbers of carbon to emitters, said Nichols. “And because of the work we’ve done for this paper, we now know that there’s a lot more carbon that can be released to the atmosphere than we thought,” he said.
Holy Moly. These projected temperatures are in Celsius.
The loss of Arctic sea ice is a primary reason for the extreme increase in projected surface air temperature by end of century https://t.co/ERXyrG5lEl
— Prof. Jason Box (@climate_ice) October 23, 2019
Wildlife failed to breed in Greenland during 2018.
"The worrying perspective is that 2018 may offer a peep into the future, where increased climatic variability may push the arctic species to — and potentially beyond — their limits." #arctic @ProjectEarth https://t.co/3A0USvDPgQ
— EcoWatch (@EcoWatch) October 21, 2019
From EcoWatch on the breeding collapse:
Zackenberg, Northeast Greenland received such heavy snow in 2018 that much of the ground remained covered well into late summer, which appears to have prevented plants and animals there from breeding. In a study published this week in the journal PLOS Biology, researchers said this led to “the most complete reproductive failure” across the whole ecosystem in more than 20 years of monitoring.
“One non-breeding year is hardly that bad for high-arctic species,” lead author Niels Martin Schmidt of Aarhus University in Denmark said in a press release. “The worrying perspective is that 2018 may offer a peep into the future, where increased climatic variability may push the arctic species to — and potentially beyond — their limits.”
During the summer, the Arctic tundra is usually a thriving habitat for a number of migratory bird species, the insects they come to feed on, highly adapted flowers and even mammals such as the Arctic fox and musk ox, according to Smithsonian.com.