Carbon uptake in Tibetan Plateau soil may offset melting permafrost carbon release

May 9, 2017 by Bob Yirka, Phys.org report
Natural-colour satellite image of the Tibetan Plateau. Credit: NASA

(Phys.org)—An international team of researchers has found that carbon uptake in the Tibetan Plateau may actually offset the carbon that is released as permafrost melts. In their paper published in the journal Nature Geoscience, the team describes soil readings they analyzed from the region and what their findings suggest about carbon release in cold parts of the world.

Anyone paying attention to the science surrounding has heard about the problem of released into the atmosphere due to melting in colder parts of the planet. Less well known or understood is what happens to the above the permafrost. As temperatures rise, soil above the permafrost becomes warmer, offering a haven for new plant growth—such plants have been found to sequester carbon from the air back into the soil. Thus, as more carbon is released from below, more is sequestered from above, but is it possible that new sequestering offsets old release? That is what the researchers with this new effort want to know. To learn more, they studied taken from multiple sites in the Tibetan Plateau (a large elevated plateau north of the Himalayas) in the early 2000s and compared them with similar samples taken a decade later.

The researchers report that the soil samples were taken from depths up to 30 cm (which is above the permafrost line) and found an average accumulation of carbon in the soil to have occurred at a mean rate of 28.0 g cm−2 yr−1, which they concluded was due to accumulation of organic carbon concentrations (material left when plants died). They describe the increase as substantial, and possibly enough to offset carbon released due to permafrost melting. More tests will have to be conducted to determine if there is a true offset, but the study results suggest that climate change models might have to be adjusted if offsetting occurs in regions much farther north. If carbon released by melting permafrost in Russia, Canada and other parts of the world is offset by new plant growth, it is possible that much less carbon will make its way into the atmosphere than has been predicted, resulting in slower than predicted global warming.

Explore further: Study shows microbes may accelerate loss of permafrost in Greenland

More information: Jinzhi Ding et al. Decadal soil carbon accumulation across Tibetan permafrost regions, Nature Geoscience (2017). DOI: 10.1038/ngeo2945

Abstract
Permafrost soils store large amounts of carbon. Warming can result in carbon release from thawing permafrost, but it can also lead to enhanced primary production, which can increase soil carbon stocks. The balance of these fluxes determines the nature of the permafrost feedback to warming. Here we assessed decadal changes in soil organic carbon stocks in the active layer—the uppermost 30 cm—of permafrost soils across Tibetan alpine regions, based on repeated soil carbon measurements in the early 2000s and 2010s at the same sites. We observed an overall accumulation of soil organic carbon irrespective of vegetation type, with a mean rate of 28.0 g C m−2 yr−1 across Tibetan permafrost regions. This soil organic carbon accrual occurred only in the subsurface soil, between depths of 10 and 30 cm, mainly induced by an increase of soil organic carbon concentrations. We conclude that the upper active layer of Tibetan alpine permafrost currently represents a substantial regional soil carbon sink in a warming climate, implying that carbon losses of deeper and older permafrost carbon might be offset by increases in upper-active-layer soil organic carbon stocks, which probably results from enhanced vegetation growth.

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6 comments

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EarthlingToo
2.6 / 5 (5) May 09, 2017
Stop the presses!

"The study results suggest that climate change models might have to be adjusted."

"It is possible that much less carbon will make its way into the atmosphere than has been predicted, resulting in slower than predicted global warming."

The AGW cult will not be happy about this; how dare anyone question their models? Don't we know the science is settled on the issue?

SMH...
MR166
2.6 / 5 (5) May 09, 2017
How many billions are being wasted on non-productive research like this?

This so called science will go down in history as the most expensive fraud ever perpetrated on mankind. Our schools have produced a scientific miracle in that they produce 100s of thousands of identical snowflakes every year.
MR166
2.6 / 5 (5) May 09, 2017
At least the research into alternate energy will eventually supplement or replace finite carbon fuels. But faulty climate science is just a waste of our precious mental and physical resources.
CSPhD
5 / 5 (2) May 10, 2017
How many billions are being wasted on non-productive research like this?


We have an old adage in computer science: "garbage in, garbage out." In essence, the results you get from a computer system are only as good as the data that is input and the program that is used to process that data. If the data, the program, or both are garbage, then the results are useless. Research like this will help improve the program - the climate model in this case - so that it is a little less "garbage" and a little more useful. (We also need to increase the coverage of the climate data we collect for input.) Given the results so far, there are likely a considerable number of feedbacks yet to be discovered and studied. We need to find and understand as many of them as we can so that, some day, we can get useful results from the models. Then we'll be able to make more informed decisions about the carbon dioxide and myriad other byproducts of our civilization we put into the environment.
MR166
2.3 / 5 (3) May 10, 2017
CS I agree with your points 100%, especially the points about GIGO and unknown feedback loops. To make matters worse there is ample proof that historical temperature records have been "adjusted" adding to the garbage in problem. The political aspect of climate change is a real problem. Powerful people are trying to get the voters to spend trillions for a solution to a problem that we cannot prove even exists.
zz5555
5 / 5 (2) May 10, 2017
Research like this will help improve the program - the climate model in this case - so that it is a little less "garbage" and a little more useful.

Given the success that climate models have had in projecting the long term temperature trends, it's rather difficult to see how "garbage in, garbage out" would apply to them. Yes, the efforts by the anti-science groups have been pretty successful in misinforming laymen (e.g., the graph from Christy), but those familiar with the science understand that the results have been pretty good (http://www.climat...vations/ ). There are always improvements to make, but at this point it would appear they'll make marginal improvements rather than a radical change in the projections.

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