Nature Climate Change | Climate Feedback

Warming speeds carbon release from peat

Northern peatlands, typical for subarctic Scandinavia and Russia, contain one third of the world’s soil organic carbon. How much extra carbon these soils will release to the atmosphere, through accelerated respiration in a warmer climate, has been pretty much guesswork. Data from an eight-year in situ experiment carried out in Sweden now suggest that even modest warming will release enough extra carbon to effectively equalize the European Union’s emissions reductions achieved under the Kyoto Protocol.

Abisko.jpg

Ellen Dorrepaal and her colleagues studied ecosystem response to climate warming at a test site near the Swedish Abisko scientific research station, some 200 kilometres inside the Arctic Circle. In a paper in Nature today (subscription required) they report that warming accelerated the respiration of carbon in peat overlaying the permafrost by almost 70 % – much more than previously thought. Here’s an editor’s summary.

Extrapolated to the total northern peatland area, the results suggest that climate warming of 1 degree Celsius over the next decade might lead to a global increase in respiration of 38-100 million tonnes of carbon per year. For comparison: The EU’s Kyoto target is to reduce emissions by 92 million tonnes of carbon per year.

The researchers stress that the effect is likely to last: “In contrast to long-term studies in forest, meadow and tundra ecosystems, the warming effect did not decline towards the eighth year of the study,” they write.

The net effect of warming on northern carbon reservoirs includes possible gains from increased plant growth. But in Arctic ecosystems dominated by peat and moss, there are too few productive woody shrubs growing to offset the warming effect on soils.

Quirin Schiermeier

Image: Subarctic peatland in Abisko, North Sweden where the consequences for CO2-respiration rates were investigated. Credit: Ellen Dorrepaal

Comments

  1. Report this comment

    Stephen Moore said:

    Peat bogs are as important as rainforests for capturing greenhouse gases, but don’t get as much publicity.

    The United Nations Environment Programme (UNEP) found in 2007 that the Earth’s estimated 988 million acres of peatlands are capable of storing about two trillion tonnes of CO2. That’s about a century’s worth of fossil fuel emissions. But peatlands are relatively small compared to their importance to the Earth’s eco-system. They only account for about 3% of the planet’s total surface.

    The Head of UNEP, Achim Steiner observed that, “just like a global phase out of old, energy-guzzling lightbulbs or a switch to hybrid cars, protecting and restoring peatlands is perhaps another key ‘low-hanging fruit’ and among the most cost-effective options for climate change mitigation”.

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    kturk said:

    Sorry, there are countries still does not accept the Kyoto Protocol. To me, first must be convinced of these countries. Europe’s efforts can not only save the world.

    Everyone in front of the house is sweeping the whole street is cleared.

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    w.h.siemonsma said:

    Ellen Dorrepaal told the Dutch press today that there is only one way to prevent that peatlands give more C02 to the atmosphere: no more global warming… I can tell her she can sleep quiet: temperature is cooling down.. May be she and her co-authors proved that there is evidence enough that more C02 is not the cause of global warming… The opposit: C02 follows the global warming… Also: there is no need to spend millions in Copenhague. Sleep well.