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Stunning Peatlands Amplifying Feedback: Drying Wetlands and Intensifying Wildfires Boost Carbon Release Ninefold

By Joe Romm on November 3, 2011 at 6:34 pm

"Stunning Peatlands Amplifying Feedback: Drying Wetlands and Intensifying Wildfires Boost Carbon Release Ninefold"

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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 research.

http://www.bt.com.bn/files/images/inline/20100225-rehab.jpg

The most dangerous amplifying carbon-cycle feedback we face in the near term is, I believe, the thawing northern tundra.  It is poised to turn the Arctic from a carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100, according to a 2011 study.

That study found, conservatively, that carbon emissions from a thawing permafrost are “strong enough to cancel 42-88% of the total global land sink. The thaw and decay of permafrost carbon is irreversible” and accounting for it “will require larger reductions in fossil fuel emissions to reach a [given] target atmospheric CO2 concentration.

But there are a host of other very serious amplifying feedbacks — or vicious circles — whereby an initial warming leads to changes that cause more emissions, which in turn lead to more warming (see partial list at end).  One of those involves the drying of the peatlands.

Most of the world’s wetlands are peat, which are better known as bogs, moors, mires, and swamp forests. Wikipedia notes, “Under the proper conditions, peat is the earliest stage in the formation of coal.” Here’s why peatlands contain so much carbon:

Peat is the accumulation of partially decayed vegetation in very wet places and it covers about two percent of global land mass. Peatlands store large amounts of carbon owing to the low rates of carbon breakdown in cold, waterlogged soils.

A 2008 Nature Geoscience study — “High sensitivity of peat decomposition to climate change through water-table feedback” — projects that “a warming of 4°C causes a 40% loss of soil organic carbon from the shallow peat and 86% from the deep peat” of Northern peatlands. And that amplifying carbon cycle feedback is dangerous for three reasons:

  1. The northern peatlands are believed to store some 320 (+/- 140) billion metric tons of carbon, roughly half of what the atmosphere contains.
  2. Peatlands tend to emit much of their carbon in the form of methane, which is more than 20 times as powerful a greenhouse gas as carbon dioxide (and 100 times more powerful over a 20-year period).
  3. A warming of 4°C this century is all but inevitable if we don’t sharply reverse emissions trends quickly (see “An Illustrated Guide to the Science of Global Warming Impacts“).

Now, a new study does some experiments and makes some observations to look at the impact of drying on peatlands.  A coauthor sums it up:

“Currently, peatlands are considered important global stores for carbon. But we’ve shown that human disturbance or climate-induced drying can switch peatlands from sinks to potentially huge sources of carbon, with losses associated with severe burning far outweighing long-term rates of sequestration.”

The full study is behind a firewall here.  The University of Guelph news release does a good job of explaining what they did and what they found:

CLICK HERE TO READ MORE OR COMMENT

The 2003 Erickson Creek Fire burned more than a month and affected about 48,000 hectares of boreal forest.

“Russia, Indonesia and Canada all have abundant peatlands, but they also have been hotspots for intense peat fires in the past decade,” said Guelph professor Merritt Turetsky, who worked on the study with William Donahue of the Water Matters Society of Alberta and Brian Benscoter from Florida Atlantic University.

In pristine states, peatlands often resist fire because of their wet soils. “Our study shows that when disturbance lowers the water table, that resistance disappears and peat becomes very flammable and vulnerable to deep burning,” she said.

Recently, destructive peat fires plagued the Moscow region. In the late 1990s, severe Indonesian fires in drained peatlands released carbon equivalent to 40 per cent of annual global fossil fuel emissions.

I discussed the research on Indonesia peatlands here:  “For Peat’s Sake, Stop the Palm Oil Madness.”

Peatlands store vast amounts of carbon by pulling carbon dioxide out of the atmosphere. For millennia, they’ve accumulated plant debris — the remains of wood, moss, and other plants — and locked it up in layers of saturated peat more than five metres deep in places.

Northern peat covers large swaths of the landscape. Because about half of that peat consists of carbon, it is a globally important carbon pool.

But peatlands are also carbon sources, as this same debris fuels wildfires. “While fire is a widely recognized disturbance in upland forests, the impacts of fire on peatlands and their carbon storage have been largely overlooked,” said Benscoter.

The majority of the world’s peatlands are located in northern regions, and Canada is home to some of the largest on the planet….

Boreal wildfirePrevious studies have documented the effects of land use practices and global warming on the ecology of peatlands. “But we wanted to examine how decades of lowered water table in peatlands might affect wildfire behaviour, and that required a very large experiment.”

To determine those effects, the researchers used a unique outdoor laboratory. A large section of a boreal fen near Slave Lake, Alta., had been drained over 20 years ago in a wetland drainage project. A portion of the fen including drained and pristine plots burned in a wildfire in 2001 allowed for a natural experiment.

Earlier research had documented increases in tree growth and carbon storage after drainage. “But nobody had looked at the impacts of dewatering on fire intensity and associated carbon gains or losses,” Donohue said.

The results were surprising, he said. Long-term drainage actually increased tree productivity and carbon storage in the fen soils. But the lower water table also changed wildfire conditions, and losses of soil carbon to burning in the drained areas increased ninefold.

“Even though the organic matter accumulation doubled over two decades after drainage, severe burning triggered the complete loss of this newly stored carbon, plus a further 450 years’ worth of peat accumulation,” Donahue said.

This study — along with the earlier work on peatlands and tundra — provides yet more evidence that the carbon cycle has a point of no return beyond which it becomes all but impossible to stop catastrophic global warming — the point at which we start to lose carbon rapidly from the northern peatlands and the permafrost (see Tundra, Part 2: The point of no return).

Again, the people out there who think R&D or an energy quest is going to stop us from multiple catastrophes are deluding themselves and others.  We need to start aggressive mitigation now as every major independent study concludes — see Study Confirms Optimal Climate Strategy: Deploy, Deploy, Deploy, Research and Develop, Deploy, Deploy, Deploy.

Related posts and amplifying feedbacks:

  • Science: Vast East Siberian Arctic Shelf methane stores destabilizing and venting:  NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.” Methane and carbon release from the Arctic is the most dangerous amplifying feedback in the entire carbon cycle. This research finds a key “lid” on “the large sub-sea permafrost carbon reservoir” near Eastern Siberia “is clearly perforated, and sedimentary CH4 [methane] is escaping to the atmosphere.”

 

 

 

 

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13 Responses to Stunning Peatlands Amplifying Feedback: Drying Wetlands and Intensifying Wildfires Boost Carbon Release Ninefold

  1. prokaryotes says:

    Risk Assessment

    Things which can go wrong

    Soil carbon and climate change: from the Jenkinson effect to the compost-bomb instability
    http://climateforce.net/2011/07/14/soil-carbon-and-climate-change-from-the-jenkinson-effect-to-the-compost-bomb-instability/

    • Raul M. says:

      That particulate forcing to help keep the watts per meter squared number low depends on an assumption of the elec. co’s continued ability to deliver elec…
      If it isn’t being delivered then the forcing isn’t there?
      Also the assumption of lowering ch4 is anthropogenic not nature forcing?

  2. mike Roddy says:

    Another important post, Joe.

    The carbon cycle in the boreal forests is one of the most important and least understood. I once started a peat fire from a campfire in northern British Columbia- it was strange, moving below ground as slow smokey combustion, and it was very hard to put out (fortunately we were next to a creek).

    Besides getting off fossil fuels, we need to encourage natural resiliency in the Boreal, which is best done by leaving them alone. The other schemes- biomass plantations, cookie cutter industrial logging, etc- change microclimates and precipitation patterns, and result in peat fires and tree death from beetles and other opportunistic pests.

    Please continue this thread.

  3. Joan Savage says:

    One of the generalities about nutrient-cycling and soils is a difference between hotter and cooler climates.

    In a perennially hot climate, essential nutrients cycle from one living organism to another, with only brief moments in dying or decaying organisms. The soil beneath a tropical rainforest may be a poor soil with few nutrients, while above it the cycles move efficiently like an on-demand economy. Remove the tissue of tropical rainforest, and the soil left behind has little to offer to support grazing land.

    In cooler climates, nutrient cycles are more likely to involve storing nutrients in dormant materials like peat or other organic soil or mineral soil. The cation exchange capacity (CEC) of the peat and other organic soils acts like a sponge, retaining nutrients. It is more like the old-fashioned storehouse kind of economy. Burn the peat or allow it to biodegrade from rapid microbial process, and the ecosystem loses much of its capacity to retain nutrients.

    I mention this matter because the longer the delay, the more nutrient loss, and it gets harder to grow substantial new vegetation that can either retain carbon in biomass or in soil accumulation.
    (Biochar fans take note.)

  4. Theodore says:

    One point about positive climate feedback loops not made often enough is the fact that the loops do not each simply amplify themselves independently of the others. They are all linked through the common element of temperature, so each of the feedback loops is driving all of the others. This could lead to extreme unpredictable instability.

    • Merrelyn Emery says:

      Yes Theodore, the effects are systemic. And I also echo Mike Roddy’s request to follow the peatland/tundra situation as it is obviously unfolding rapidly. Methane is now the real biggie and with the report above of the 6% rise in CO2, we can expect to see more bad news in the near future.

      And while I am contemplating all this, please also keep an eye on the PIG in Antarctica -it would be nice to have ‘ocean views’ but…

      Time to vegie out, ME

    • John McCormick says:

      Theodore, throw Arctic amplification into the scenario. MIT study points to huge temp increase in the Arctic Circle. Tundra, permafrost, fires. CO2 and CH4 bombs.

  5. Alex Smith says:

    Currently though tropical peat fires are emitting far more than Arctic peat, according to my interview with Dr. Florian Siegert of the GeoBio Centre in Munich Germany.

    He uses over a dozen satellites to monitor peat fires in Indonesia (which last month smoked out Singapore and Malaysia, as they did in 1997.)

    In ’97 a big burst of carbon came from Indonesian peat fires, making Indonesia the third largest source of greenhouse gases on the planet. The following year, 1998, is thought to be the warmest on record, or tied for the warmest.

    Right now, major corporations are clearing away tropical rainforests in Indonesia, in part to create palm oil plantations for “green” biofuel.

    Not only are the tropical forests burned off, but efforts to dry out the swampland (the only uninhabited parts left in Indonesia) – the canals dug result in tropical peat drying out – ready to burn. This all could be prevented by international action.

    Dr. Siegert says there is a vast amount of tropical peat, not just in Indonesia, but in Africa and South America. It can be up to 150 feet deep. It is not frozen.

    Why not start with the big carbon source we have right now in tropical peat? Yes, the Arctic is big, and will come later, but it will come bigger and faster if the tropical devastation of peatlands is allowed to continue (and European companies buy the palm oil as fuel…. “to save the environment”)

    Check the blog for the radio show here.
    http://www.ecoshock.info/2011/09/how-far-away-island-can-rock-your-world.html

  6. From the lesser of two evils department: If peat dries and burns, then the carbon emissions are CO2 as opposed to methane– so my understanding is that the drying process on net reduces forcing from thawing tundra. Any science folks that can help out here? Is it better to have dry, flammable thawed tundra, or wet anaerobic thawed tundra?

  7. michael allen says:

    we are screwed.

    • Pangolin` says:

      This is where in a lesser blog there would be a picture of a massive crowd engaged in a facepalm.

      This will have to do.

      Major fail humans.

  8. Eliza Olson says:

    The Burns Bog Conservation Society is fighting the South Fraser Perimeter Road that runs through peatland next to the Conservation Area.

    All levels of government (Federal, Provincial, Municipal and Metro Vancouver (formerly Greater Vancouver Regional District) have failed to uphold the Conservation Covenant.

    The Society is going to court on March 13, 2012. Regardless of what happens, we will make history. If we fail to get standing to fight/force the Federal Government over this Road, it will mean that “no” conservation covenant in Canada is worth the paper it is written on. This includes the Species at Risk Act, the Transboundary Migratory Bird Act and others. If we win, Mother Nature wins.

    Join us in our fight. Make a donation. Offer your expertise. Do whatever you can in your way to help us win this battle for Canada’s southern-most raised peat bog and the largest on the west coast of North America. Burns Bog needs you today.