Permafrost general science thread

[kassy]

Arctic Shifts To a Carbon Source Due to Winter Soil Emissions
https://eurekalert.org/pub_releases/2019-11/nsfc-ast110819.php

A NASA-funded study suggests winter carbon emissions in the Arctic may be adding more carbon into the atmosphere each year than is taken up by Arctic vegetation, marking a stark reversal for a region that has captured and stored carbon for tens of thousands of years.

The study, published Oct. 21 in Nature Climate Change, warns that winter carbon dioxide loss from the world's permafrost regions could increase by 41% over the next century if human-caused greenhouse gas emissions continue at their current pace. Carbon emitted from thawing permafrost has not been included in the majority of models used to predict future climates.

"These findings indicate that winter carbon dioxide loss may already be offsetting growing season carbon uptake, and these losses will increase as the climate continues to warm," said Woods Hole Research Center Arctic Program Director Sue Natali, lead author of the study. "Studies focused on individual sites have seen this transition, but until now we haven't had a clear accounting of the winter carbon balance throughout the entire Arctic region."

Researchers estimate a yearly loss of 1.7 billion metric tons of carbon from the permafrost region during the winter season from 2003 to 2017 compared to the estimated average of 1 billion metric tons of carbon taken up during the growing season. ... "The warmer it gets, the more carbon will be released into the atmosphere from the permafrost region, which will add to further warming," ... . If fossil fuel use is modestly reduced over the next century, winter carbon dioxide emissions would increase 17% compared with current emissions. Under a scenario where fossil fuel use continues to increase at current rates through the middle of the century, winter carbon dioxide emissions from permafrost would rise by 41%.

Reposted here because it is a rather significant find about permafrost.

Abstract:
https://www.nature.com/articles/s41558-019-0592-8

Stuff that was bolded not long ago.

We predict that the PCF will change the arctic from a carbon sink to a source after the mid‐2020s


Well that failed.

Furthermore, there is high confidence that climate scenarios that involve mitigation (e.g. RCP4.5) will help to dampen the response of carbon emissions from the Arctic and boreal regions.


What really helps if you force the world onto that path. Or something even better.

Basically there is only one important scenario, the one we call the world.

We should go zero quicker and more coordinated and employ a bunch of cheap sensible carbon capture techniques ASAP which is ofc not going to happen.

The earlier 2020 date triggered me because one of the goals always was to prevent things like this from happening and now it is already here.

Eyeballing Mauna Loa CO2 anything over 370 is bad. So that is an interesting challenge.

[bluesky]

Geophysical Research Letters

Research Letter  Open Access

Rapid CO2 Release From Eroding Permafrost in Seawater
G. Tanski  D. Wagner  C. Knoblauch  M. Fritz T. Sachs  H. Lantuit
First published: 15 October 2019
https://doi.org/10.1029/2019GL084303
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Abstract
Permafrost is thawing extensively due to climate warming. When permafrost thaws, previously frozen organic carbon (OC) is converted into carbon dioxide (CO2) or methane, leading to further warming. This process is included in models as gradual deepening of the seasonal non‐frozen layer. Yet, models neglect abrupt OC mobilization along rapidly eroding Arctic coastlines. We mimicked erosion in an experiment by incubating permafrost with seawater for an average Arctic open‐water season. We found that CO2 production from permafrost OC is as efficient in seawater as without. For each gram (dry weight) of eroding permafrost, up to 4.3 ± 1.0 mg CO2 will be released and 6.2 ± 1.2% of initial OC mineralized at 4 °C. Our results indicate that potentially large amounts of CO2 are produced along eroding permafrost coastlines, onshore and within nearshore waters. We conclude that coastal erosion could play an important role in carbon cycling and the climate system

Rapid CO2 Release From Eroding Permafrost in Seawater
G. Tanski  D. Wagner  C. Knoblauch  M. Fritz T. Sachs  H. Lantuit
First published: 15 October 2019
https://doi.org/10.1029/2019GL084303

[kassy]

Thanks!

From the PLS:
A slow and continuous thaw is currently used in models to project future greenhouse gas release from permafrost. Yet along the rapidly eroding coastlines of the Arctic Ocean, which make up 34% of the Earth's coastlines, whole stretches of the coast simply collapse, sink or slide into the ocean, including the previously frozen organic carbon.

Bolded: i would never have guessed it was that much.

[kassy]

Shrubbier tundra likely accelerates permafrost thawing, study finds
Social Sharing

Areas with dwarf birch saw faster snow melt and deeper ground thawing

...

While their impact varies, a paper recently published in the journal, Arctic Science, found areas with birch shrubs had longer snow-free periods, in turn accelerating the thawing of the ground below.

"We discovered that the date at which the snow melts is a key driver in how deep the ground will thaw in the summer," said Evan Wilcox, a geography PhD candidate at Wilfrid Laurier University and the paper's lead author.

"Areas where the shrubs protrude through [the snow], the snow melts on average a week earlier," he said. Taller shrubs paired with warmer air temperatures will likely result in more permafrost thawing, he said.

for details see:
https://www.cbc.ca/news/canada/north/arctic-tundra-permafrost-thaw-shrub-1.5359354

and

Tundra shrub expansion may amplify permafrost thaw by advancing snowmelt timing

https://www.nrcresearchpress.com/doi/10.1139/as-2018-0028#.Xc6YDVdKjct

[gerontocrat]

The essay linked below is in the NOAA 2019 Arctic Report Card https://arctic.noaa.gov/Report-Card/Report-Card-2019
Basically, winter CO2 emissions grossly underestimated and more than CO2 capture in the Summer by 0.6 petagrams of CARBON per annum.

To us simple people it is 0.6 x 3.67 = 2.2 GT of CO2 - a significant amount meaning a carbon sink is a actually a carbon emitter.

Extracts.....
https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle
Permafrost and the Global Carbon Cycle

Highlights
- Northern permafrost region soils contain 1,460-1,600 billion metric tons of organic carbon, about twice as much as currently contained in the atmosphere.
- This pool of organic carbon is climate-sensitive. Warming conditions promote microbial conversion of permafrost carbon into the greenhouse gases carbon dioxide and methane that are released to the atmosphere in an accelerating feedback to climate warming.
- New regional and winter season measurements of ecosystem carbon dioxide flux independently indicate that permafrost region ecosystems are releasing net carbon (potentially 0.3 to 0.6 Pg C per year) to the atmosphere.
- These observations signify that the feedback to accelerating climate change may already be underway.

Introduction
The Arctic continues to warm at a rate that is currently twice as fast as the global average (see essay Surface Air Temperature). Warming is causing perennially-frozen ground (permafrost) to thaw, with permafrost in many locations currently reaching record high temperatures (Biskaborn et al. 2019). Organic carbon contained in soils of the permafrost region represent a climate-sensitive carbon reservoir that is affected by warming air and ground temperatures and permafrost thaw....

The northern permafrost region holds almost twice as much carbon as is currently in the atmosphere. Additional net releases of carbon dioxide (CO2) and methane (CH4) to the atmosphere as a result of warming and faster microbial decomposition of permafrost carbon have the potential to accelerate climate warming. ....

Permafrost carbon pools: How much permafrost carbon is available to release into the atmosphere?
The new, best mean estimate of the amount of organic carbon stored in the northern permafrost region is 1,460-1,600 petagrams (Pg; 1 Pg = 1 billion metric tons) (Hugelius et al. 2014; Schuur et al. 2015). Of this inventory, 65-70% (1,035 ± 150 Pg) of the carbon is within the surface layer (0-3 m depth) (Fig. 1). Soils in the top 3 m of the rest of Earth's biomes (excluding Arctic and boreal biomes) contain 2,050 Pg of organic carbon (Jobbagy and Jackson 2000). The soil carbon from the northern circumpolar permafrost region adds another 50% to this 3-m inventory, even though it occupies only 15% of the total global soil area (Schuur et al. 2015).

Ecosystem-atmosphere carbon exchange: Is the Arctic currently releasing additional net carbon dioxide emissions to the atmosphere?
....
A new comprehensive synthesis study of non-summer ecosystem CO2 fluxes across the circumpolar region showed that carbon release during the Arctic winter was 2 to 3 times higher than previously estimated from ground-based measurements (Fig. 3) (Natali et al. 2019). This circumpolar estimate suggests that carbon release in the cold season offsets net carbon uptake during the growing season (derived from models) such that the region as a whole could already be a source of 0.6 Pg C per year to the atmosphere.

[TerryM]

^^
Northern Ontario's vast permafrost regions seem destined to emit large quantities of GHGs regardless of what steps we take.  To the east of James Bay in Northern Quebec, the flooding of an area twice the size of Scotland with relatively warm water will speed the melting of the permafrost layers and increase GHG emissions year round. The Eastmain Hydro project is being expanded and will again be the world's largest producer of hydroelectric power.
These emissions don't appear on your charts - yet.


The warmest, most southerly permafrost regions are presently the largest emitters, but as the Arctic warms the melting regions will expand, and emissions will expand with them. The last time this occurred we had turtles, alligators and primates living year round on Ellesmere Island. Six months without insolation apparently wasn't enough to freeze them out.


I question whether primates will survive this accelerated warming.
Terry

[Juan C. García]

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

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.

https://www.washingtonpost.com/weather/2019/12/10/arctic-may-have-crossed-key-threshold-emitting-billions-tons-carbon-into-air-long-dreaded-climate-feedback/?wpisrc=al_environment__alert-hse&wpmk=1

[ArcticMelt2]

https://twitter.com/ckatz99/status/1205573106972033024

[nanning]

^^
I don't understand that presentation.
It reads:

5% - 15% (vulnerable fraction of permafrost)
146 - 160 billion tons (emissions)

160?

15% should be 3*146 = 438GT I think. A 'bit' more than 160GT.

Or 5% should be 160/3 = 53GT. A 'bit' less than 146GT.

That's a lot of carbon (75ppm in the presentation) and the "5% - 15%" may well increase to "5% - 20%" or more in the future with new and better understanding.

[kassy]

The slide could be clearer. See the report card quote in #54 above.

Northern permafrost region soils contain 1,460-1,600 billion metric tons of organic carbon

So that number is the total in play but working out the emissions is not straightforward.
I think the 5-15% is also a base input.

It would be nice to have a name of a scientist or an article to go with the slide (not a Twitter fan but looking at the feed it seems to come from the Report Card so delve into that to see how they arrive at the numbers.

[gerontocrat]

^^
I don't understand that presentation.
It reads:

5% - 15% (vulnerable fraction of permafrost)
146 - 160 billion tons (emissions)

160?

15% should be 3*146 = 438GT I think. A 'bit' more than 160GT.

Or 5% should be 160/3 = 53GT. A 'bit' less than 146GT.

That's a lot of carbon (75ppm in the presentation) and the "5% - 15%" may well increase to "5% - 20%" or more in the future with new and better understanding.

Total Arctic Permafrost (on land) is estimated to contain 1400 to 1600 GT of CARBON.

The 140-160 GT guess of possible carbon emissions from Arctic permafrost to 2100 in the presentation is 10%, i.e. the mid-point of 5% to 15%.

If released as CO2 that is 160 GT of carbon x 3.67 = 590 GT of CO2.

1 ppm of atmospheric CO2 = 7.81 GT

So 160 GT of carbon released into the atmosphere equates to 75 ppm.

But that ignores any increase in absorption by the carbon sinks (currently 50%)
BUT who knows what the future of carbon sinks will be? Most of the news is not good about either the land or the ocean sinks.

The presentation also does not consider possible CO2 and CH4 emissions from undersea permafrost (e.g. from the shallow East Siberian Arctic Shelf).

A recent paper suggests that current emissions may already be at about 2.2 GT of CO2 per annum, i.e. if continued at that rate to 2100 = 176 billion GT of CO2. Obviously AGW + polar amplification would increase that rate substantially.
(see post #54 by me above)
Link is https://arctic.noaa.gov/Report-Card/Report-Card-2019/ArtMID/7916/ArticleID/844/Permafrost-and-the-Global-Carbon-Cycle

[nanning]

I haven't read the Report Card, sorry. I've lost my interest in details I think.
Thank you for explaining and for your view gerontocrat.

It would be nice to have a name of a scientist or an article to go with the slide

That would've been nice in retrospect (I thought it was an error).
And thank you for your response.