ScienceDaily (Nov. 29, 2010) — The rate of global warming could lead to a rapid release of carbon from peatlands that would further accelerate global warming.

Two recent studies published by the Mathematics Research Institute at the University of Exeter highlight the risk that this 'compost bomb' instability could pose, and calculate the conditions under which it could occur.

The same Exeter team is now exploring a possible link between the theories described in the studies and last summer's devastating peatland fires in Russia.

The first paper is published in the European Journal of Social Science and the second in Proceedings of the Royal Society A.

The first paper by Catherine Luke and Professor Peter Cox describes the basic phenomenon. When soil microbes decompose organic matter they release heat -- this is why compost heaps are often warmer than the air around them.

The compost bomb instability is a runaway feedback that occurs when the heat is generated by microbes more quickly than it can escape to the atmosphere. This in turn requires that the active decomposing soil layer is thermally-insulated from the atmosphere.

Catherine Luke explains: "The compost bomb instability is most likely to occur in drying organic soils covered by an insulating lichen or moss layer."

The second paper led by Dr Sebastian Wieczorek and Professor Peter Ashwin, also of the University of Exeter, proves there is a dangerous rate of global warming beyond which the compost bomb instability occurs.

This is in contrast to the general belief that tipping points correspond to dangerous levels of global warming.

Sebastian Wieczorek explains: "The compost bomb instability is a novel type of rate-dependent climate tipping point."

The Exeter team is now modelling the potential impact of the compost bomb instability on future climate change, including the potential link to the Russian peatland fires.It is also working to identify other rate-dependent tipping points.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of Exeter, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal References:

1. C. M. Luke, P. M. Cox. Soil carbon and climate change: from the Jenkinson effect to the compost-bomb instability. European Journal of Soil Science, 2010; DOI: 10.1111/j.1365-2389.2010.01312.x
2. S. Wieczorek, P. Ashwin, C. M. Luke, P. M. Cox. Excitability in ramped systems: the compost-bomb instability. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2010; DOI: 10.1098/rspa.2010.0485

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Related Stories

Northern Peatlands a Misunderstood Player in Climate Change (Mar. 17, 2011) — Researchers have determined that the influence of northern peatlands on the prehistorical record of climate change has been over estimated, but the vast northern wetlands must still be watched ...  > read more

Climate Change And Permafrost Thaw Alter Greenhouse Gas Emissions In Northern Wetlands (Aug. 13, 2007) — Permafrost -- the perpetually frozen foundation of North America -- isn't so permanent anymore, and scientists are scrambling to understand the pros and cons when terra firma goes soft. Permafrost ...  > read more

Wetlands: Drying Intensifying Wildfires, Carbon Release Ninefold, Study Finds (Nov. 2, 2011) — Drying of northern wetlands has led to much more severe peatland wildfires and nine times as much carbon released into the atmosphere, according to new ...  > read more

Northern Wildfires Threaten Runaway Climate Change, Study Reveals (Dec. 6, 2010) — A new study reveals that fires in the Alaskan interior have become more severe in the last decade, resulting in more carbon being released than is being stored. About half the world's soil carbon is ...  > read more

Search ScienceDaily