Study shows microbes may accelerate loss of permafrost in Greenland

Study shows microbes may accelerate loss of permafrost in Greenland
Among the best preserved kitchen-middens in the world, the Qajaa site has until now been preserved by permafrost in one of the most Northern World Heritage sites. Credit: Bo Elberling

(Phys.org)—A small team of researchers working in Greenland has found that as microbes become active in permafrost, they produce heat, which can increase the rate of permafrost loss. In their paper published in Nature Climate Change, the researchers, affiliated with the University of Copenhagen and the National Museum of Denmark describe simulations they created that showed possible impacts of microbe activation in permafrost areas.

In the most northern latitudes it is so cold year round that the soil and rock never thaw—that means that organic material from plants that die never has a chance to decompose. Over many years, a layer of such material has built up, which represents a tremendous carbon store. Scientists have been concerned about the impact of global warming on these regions, suggesting that if temperatures up north grow warm enough to melt the permafrost, the atmosphere is likely to see a big increase in carbon dioxide. As temperatures have risen, scientists have created models to predict a timeline for such an occurrence, but now, due to the efforts of this new research team, it appears those timelines will have be modified.

Suspecting that in the soil might have an impact on warming permafrost, the researchers collected 21 samples of permafrost soil from six sites across Greenland. They then exposed the samples to different temperatures to see what happened. By carefully monitoring heat production by the microbes in the soil they were able to gather enough information to create a computer simulation. That simulation showed that as rise, a feedback loop occurs in permafrost areas. Heat causes melting which paves the way for microbes, as they decompose , they produce heat which adds to the increased temperatures, and on and on presumably until all of the material in the permafrost has been melted and decomposed, releasing massive amounts of carbon into the air far earlier than previous models have predicted.

The researchers also note that as the northern regions warm, evidence left behind over thousands of years by people venturing into the region will begin to decay as well as it begins to thaw along with the .


Explore further

Computer sims: In climatic tug of war, carbon released from thawing permafrost wins handily

More information: Permafrost thawing in organic Arctic soils accelerated by ground heat production, Nature Climate Change, http://www.nature.com/articles/DOI: 10.1038/nclimate2590

Abstract

Decomposition of organic carbon from thawing permafrost soils and the resulting release of carbon to the atmosphere are considered to represent a potentially critical global-scale feedback on climate change. The accompanying heat production from microbial metabolism of organic material has been recognized as a potential positive-feedback mechanism that would enhance permafrost thawing and the release of carbon. This internal heat production is poorly understood, however, and the strength of this eect remains unclear. Here, we have quantified the variability of heat production in contrasting organic permafrost soils across Greenland and tested the hypothesis that these soils produce enough heat to reach a tipping point after which internal heat production can accelerate the decomposition processes. Results show that the impact of climate changes on natural organic soils can be accelerated by microbial heat production with crucial implications for the amounts of carbon being decomposed. The same is shown to be true for organic middens5 with the risk of losing unique evidence of early human presence in the Arctic.

Journal information: Nature Climate Change

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Citation: Study shows microbes may accelerate loss of permafrost in Greenland (2015, April 7) retrieved 23 July 2019 from https://phys.org/news/2015-04-microbes-loss-permafrost-greenland.html
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Apr 07, 2015
If the AGW deniers were truly scientists or even rational they should be able to admit error when faced with increasing observations and data sets.
As to the abstract: "This internal heat production is poorly understood, however, the strength of the eect (sic) remains unclear." Anyone with a backyard compost heap should already understand that unless the heap is periodically turned a build up of methane gas within may cause spontaneous combustion. As the northern hemisphere's permafrost recedes an incalculable amount of methane prepares to be emitted into the atmosphere. AGW may just be a spark or a lit match, nature can take it from here.
Nero fiddled as Rome burned.

Apr 07, 2015
I do not understand how some can be so politically-manipulated they continue to oppose our efforts to save the environment for Humans.

Since they got suckered by those two draft-dodging cowards screaming "WMD!", and "Bring 'em on!", they assume we are all vulnerable to control.

This is a terrible finding, since methane has a much more intense effect on GW. This positive feedback can kill us.

Apr 08, 2015
Just wait until the frozen methane ice at the bottom of the oceans starts melting. We ain't seen nothin', yet.

http://en.wikiped...lathrate

Come on folks! The idea of "knock on effects" isn't that hard to understand.

Apr 09, 2015
I do not understand how some can be so politically-manipulated they continue to oppose our efforts to save the environment for Humans.


I don't know who opposes efforts to help the environment from a human perspective. What I think some question is how literally we take predictions and how emotionally we react to their claims of imminent doom. I think we should take rational action to curb our use of resources, including fossil fuels... being less wasteful would be the biggest key to keeping such a large population of people on this planet... however I also acknowledge that whatever action we do take will likely have a very MINIMAL impact on the climate. Whatever is happening was inevitable but perhaps we made it happen slightly sooner. That carbon in the permafrost was free and active in the environment prior to the last Ice Age. It's not unnatural. It was simply waiting for the right conditions to become part of the cycle again. This is not new territory for the planet.

Apr 09, 2015
This is not new territory for the planet.


Rates matter, though. Glacial melting happened on time scales of thousands of years. This gives time for species to slowly drift from one place to another (particularly plants who happen to be a bit rooted where they are) and adapt along the way.

What we're seeing right now is a deglaciation happening hundreds of times faster. What took thousands of years is taking decades. That's new.

It won't eliminate life on earth, not even human life, true. But it's going to make things really hard for a lot of things on the planet. I mean... what if a comet/asteroid hit the planet and caused a glaciation event to happen over a few decades? That'd surely be a dramatic 'catastrophe' in our planet's history (see: dinosaurs and other impact events). What makes it any less 'catastrophic' if it's caused by one species on the planet itself?

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