Northern peatlands will lose some of their CO2 sink capacity under a warmer climate

April 03, 2020

A Nordic study sheds new light on the role of northern peatlands in regulating the regional climate. According to the researchers, peatlands will remain carbon sinks until the end of this century, but their sink capacity will be substantially reduced after 2050, if the climate warms significantly.

Peatlands develop in waterlogged conditions which slow down plant decomposition rates, so that layers of dead plant material accumulate over many years as peat. They are a huge storehouse for significant quantities of carbon from the atmosphere. Despite only covering around 3% of the Earth's surface, peatlands contain roughly a fifth of its soil carbon. In Europe, these ecosystems store five times more CO2 than forests.

A Nordic team of researchers used novel arctic modelling tools and previously published data on peatland carbon accumulation rates, vegetation and permafrost characteristics to study the role of northern peatlands in regulating the regional climate. A major concern is whether these ecosystems will continue to remain carbon sinks and help in mitigating climate change under changing climatic conditions. The modelling study, published in Global Change Biology, aims to address these important questions.

The model (LPJ-GUESS Peatland) used in this study captured the broad patterns of long-term peatland carbon dynamics at different spatial and temporal scales. The model successfully simulated reasonable vegetation patterns and permafrost extent across the pan-Arctic. Under contrasting warming scenarios (mild and severe), the study showed that peatlands on average continue to remain carbon sinks until the end of this century. However, their sink capacity would be substantially reduced after 2050 under the high-warming scenario due to an increase in soil mineralization rates. This modelling approach contributes to a better understanding of peatland dynamics and its role in the global climate system at different spatiotemporal scales. A major uncertainty of future predictions is the impact of formation of new peatlands with potential change in the peatland sink capacity owing to permafrost thawing and possible landscape changes.

"With this study our aim is to highlight the importance of peatlands in the global carbon cycle. We adopted an advanced peatland modelling tool to address the issues pertaining to peatland carbon balance in the past and future climate conditions. Now, our plan is to take forward our current research on the role of peatlands in regulating the regional climate by coupling our state-of-the-art peatland model with global and regional climate models in order to quantify the peatland-mediated feedbacks," says Postdoctoral Fellow Nitin Chaudhary, the lead author of the study, from the University of Oslo.

"Arctic carbon balance modelling studies working with coarse spatial resolution (half-grid scale) have often ignored the role of peatlands. This study emphasises the role of natural peatlands in the Arctic carbon balance and regional climate regulation. Such studies are needed so that their role is well defined in the global carbon models," University Researcher Narasinha Shurpali from the University of Eastern Finland says.
-end-
The study was conducted in collaboration between the University of Eastern Finland, the University of Oslo, the University of Gothenburg, Stockholm University, the University of Copenhagen and Lund University.

For further information, please contact:

Narasinha Shurpali, University Researcher
University of Eastern Finland, Kuopio
Tel: +358 50 573 9538
Email: narasinha.shurpali@uef.fi

Nitin Chaudhary, Postdoctoral Fellow
University of Oslo, Norway
Tel: +46760340970
Email: nitin.chaudhary@geo.uio.no

Research article:

Chaudhary, N., Westermann, S., Lamba, S., Shurpali, N., Sannel, A.B.K., Schurgers, G., Miller, P.A. and Smith, B. (2020), Modelling past and future peatland carbon dynamics across the pan?Arctic. Glob Change Biol. Accepted Author Manuscript. doi:10.1111/gcb.15099

University of Eastern Finland

Related Permafrost Articles from Brightsurf:

Coastal permafrost more susceptible to climate change than previously thought
Research led by Micaela Pedrazas, who earned her masters at The University of Texas at Austin Jackson School of Geosciences working with Professor Bayani Cardenas, has found permafrost to be mostly absent throughout the shallow seafloor along a coastal field site in northeastern Alaska.

Arctic Ocean sediments reveal permafrost thawing during past climate warming
Sea floor sediments of the Arctic Ocean can reveal how permafrost responds to climate warming.

Thawing permafrost releases organic compounds into the air
When permafrost thaws due to global warming, not only the greenhouse gases known to all, but also organic compounds are released from the soil.

Siberia's permafrost erosion has been worsening for years
The Arctic is warming faster than any other region on the planet.

Alaska is getting wetter. That's bad news for permafrost and the climate.
Alaska is getting wetter. A new study spells out what that means for the permafrost that underlies about 85% of the state, and the consequences for Earth's global climate.

Plant roots increase carbon emission from permafrost soils
A key uncertainty in climate projections is the amount of carbon emitted by thawing permafrost in the Arctic.

Stocks of vulnerable carbon twice as high where permafrost subsidence is factored in
Twice as much carbon in permafrost is vulnerable to microbial respiration when researchers from Northern Arizona University accounted for subsidence, the gradual sinking of terrain caused by loss of ice and soil mass.

Carbon emission from permafrost soils underestimated by 14%
Picture 500 million cars stacked in rows. That's how much carbon -- about 1,000 petagrams, or one billion metric tons - -is locked away in Arctic permafrost.

Nitrogen in permafrost soils may exert great feedbacks on climate change
A new Sino-German scientific collaboration investigating nitrogen in the soils of China's melting permafrost aims to get to the bottom of why emissions of nitrous oxide -- an often overlooked greenhouse gas -- are greater than they are supposed to be.

Patterns in permafrost soils could help climate change models
A team of scientists spent the past four summers measuring permafrost soils across a 5,000 square-mile swath of Alaska's North Slope.

Read More: Permafrost News and Permafrost Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.