Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon dioxide biggest player in thawing permafrost

14.06.2016

Carbon dioxide emissions from dry and oxygen-rich environments will likely strengthen the climate forcing impact of thawing permafrost on top of methane release from oxygen-poor wetlands in the Arctic, according to a study in Nature Climate Change.

The study, published today, was led by Northern Arizona University assistant research professor, Christina Schädel. One of her collaborators is Evan Kane, an assistant professor of soils at Michigan Technological University.


To better understand the impact of methane and carbon dioxide on climate change, ecologist Evan Kane samples thawing permafrost in Alaska.

Credit: Michigan Tech, Evan Kane

"Having the chance to be involved with such a large collaboration is important," Kane says, adding that getting a more complete understanding of the impacts of thawing permafrost requires a lot of researchers. "With this study, we're able to look at the complexity of the changing permafrost environments and offer more insight into how the carbon they hold will react as they thaw."

Greenhouse Gases

Schädel's meta-analysis of 25 Arctic soil incubation studies found that both temperature and soil conditions affected the quantity of carbon released from thawing permafrost. A 10 °C increase in soil temperature released twice as much carbon into the atmosphere, and drier, aerobic soil conditions released more than three times more carbon than wetter, anaerobic soil conditions.

Most of that carbon was in the form of carbon dioxide, mixed with a surprisingly small amount of methane--only 5 percent of the total anaerobic products. This means that even though methane packs 34 times the climate warming punch of carbon dioxide, the small quantity released relative to carbon dioxide in anaerobic conditions makes wet soils less of a concern than dry soils.

"Our results show that increasing temperatures have a large effect on carbon release from permafrost but that changes in soil moisture conditions have an even greater effect," says Schädel. "We conclude that the permafrost carbon feedback will be stronger when a larger percentage of the permafrost zone undergoes thaw in a dry and oxygen-rich environment. "

Thawing Permafrost

Scientists in the international Permafrost Carbon Network that Schädel co-leads with Northern Arizona University professor of ecosystem ecology, Ted Schuur, provided much of the data.

Kane helped provide data on how altered hydrology, specifically flooding and drought, affects organic matter decomposition. He and his team observed that the carbon dioxide to methane ratios were impacted by dry or wet soils, with carbon dioxide production favored in drying and variable scenarios. The initial findings, included in the new meta-analysis, were originally published in Soil Biology & Biogeochemistry.

As the permafrost thaws, microbes wake up and begin digesting the newly available remains of ancient plants and animals stored as carbon in the soil. This digestion produces either carbon dioxide or methane, depending on soil conditions. Scientists want to understand the ratio of carbon dioxide to methane gas released by this process because it affects the strength of the permafrost carbon feedback loop: greenhouse gases released due to thawing permafrost cause temperatures to rise, leading to even more thawing and carbon release. Furthermore, the Arctic permafrost is like a vast underground storage tank of carbon, holding almost twice as much as the atmosphere. At that scale, small changes in how the carbon is released will have big effects.

Schädel zeroed in on two factors: soil temperature and the availability of oxygen. Soils in the lab were incubated at a range of warmer temperatures projected for the future. The availability of oxygen is important because it determines how microbes digest carbon. Oxygen-rich, or aerobic, conditions are found in dry soils and produce carbon dioxide. Oxygen-poor, or anaerobic, conditions are found in wet soils and produce both carbon dioxide and methane. Lab incubations mimicked these two conditions.

Will wet or dry soils dominate the future Arctic permafrost zone? The answer to this question is a big unknown. Schädel's work, however, will strengthen existing models of the permafrost ecosystem. Her work also highlights the need to monitor changes in wetness associated with permafrost thaw, changes that ultimately sculpt the topography of waterlogged depressions and dry uplands across the Arctic landscape.

Media Contact

Christina Schadel
Christina.Schaedel@nau.edu
928-523-9588

 @michigantech

http://www.mtu.edu 

Christina Schadel | EurekAlert!

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>