Climate

For peat’s sake: A point of no return as alarming as the tundra feedback

CREDIT:

bog2.jpgA new study in Nature Geoscience (subs. req’d, abstract below) 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.
  3. A warming of 4°C this century is all but inevitable if we don’t sharply reverse emissions trends quickly (see “Is 450 ppm politically possible? Part 0: The alternative is humanity’s self-destruction“).

This study 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 the northern peatlands and the permafrost (see Tundra, Part 2: The point of no return).

Most of the world’s wetlands are peat, which are better known as bogs, moors, mires, and swamp forests. Wikipedia notes, “Under the right conditions, peat is the earliest stage in the formation of coal.” The Reuters article on the study explains 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.

The carbon cycle feedback begins as human-caused global warming dries out the peatlands:

“This will cause carbon loss from the soil which means an increase in carbon dioxide concentration in the atmosphere, which will further worsen global warming,” said Takeshi Ise from the Japan Agency for Marine-Earth Science and Technology. “So we have to do something to mitigate global warming,” he told Reuters.

This, of course, is very similar to the carbon cycle feedbacks from the melting of the tundra or permafrost (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“).

Again, if we don’t keep total warming substantially below 4°C, then we risk triggering vast releases of methane and carbon dioxide from the permafrost and the northern peatlands at rates that are much faster than humanity can plausibly reduce our own emissions.

Here is the full abstract of “High sensitivity of peat decomposition to climate change through water-table feedback”:

Historically, northern peatlands have functioned as a carbon sink, sequestering large amounts of soil organic carbon, mainly due to low decomposition in cold, largely waterlogged soils. The water table, an essential determinant of soil-organic-carbon dynamics interacts with soil organic carbon. Because of the high water-holding capacity of peat and its low hydraulic conductivity, accumulation of soil organic carbon raises the water table, which lowers decomposition rates of soil organic carbon in a positive feedback loop. This two-way interaction between hydrology and biogeochemistry has been noted but is not reproduced in process-based simulations. Here we present simulations with a coupled physical–biogeochemical soil model with peat depths that are continuously updated from the dynamic balance of soil organic carbon. Our model reproduces dynamics of shallow and deep peatlands in northern Manitoba, Canada, on both short and longer timescales.

We find that the feedback between the water table and peat depth increases the sensitivity of peat decomposition to temperature, and intensifies the loss of soil organic carbon in a changing climate. In our long-term simulation, an experimental warming of 4°C causes a 40% loss of soil organic carbon from the shallow peat and 86% from the deep peat. We conclude that peatlands will quickly respond to the expected warming in this century by losing labile soil organic carbon during dry periods.

Finally, global peatlands contain over twice the carbon as northern peatlands — and while tropical peatlands are unlikely to dry out from human-caused global warming, they can and are being destroyed directly by humans (see “Stop the Palm Oil Madness“).

We have indeed met the enemy, and he is us.

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15 Responses to For peat’s sake: A point of no return as alarming as the tundra feedback

  1. paulm says:

    Hope there aren’t any substantial Southern peatlands.

    I guess were pretty much at the threshold here. Adaptation has now probably got to be the main focus.

    [JR: I don’t think adaptation is a meaningful term here. Triage and misery seem more accurate.]

  2. John McCormick says:

    Paulm,

    with global temperature projected to rise as CO2 concentration increases steadily, adaptation, in its broadest interpretation, becomes impossible since we cannot adapt rapidly enough to moving targets.

    That said, in a much narrower sense, a generation adapting to drier conditions, in agricultural regions, is comon sense. Drip irrigation, more drought tolerant crops and adjusted planting and harvesting schedules will be used to keep producion up but not likely increasing.

    Next generations will have to move the bar up from their ancestors but there are obvious limits and Australians are telling us they have reached limits for wheat harvest unless conditions dramatically improve.

    Adaptation is human nature but not universally possible if people do not have wealth and resources to exploit.

    Short term — adapt one’s lifestyle to live within one’s means.

    Long term — Joe got it right; triage and misery.

    John McCormick

  3. john says:

    Adaptation, paulm? Why yes, I’m sure you’re right. And while we’re at it let’s calculate the amount of carbon sequestered when we bury the dead bodies of those who couldn’t adapt.

    Paulm, why — when we still have a sliver of time to act — would you preemptively capitulate to what will surely be the most devastating catastrophe ever to be experienced by humanity? All the worse for being self-inflicted.

    There is no adaptation to the warming that would be induced by this kind of event — there is only survival, at the basest level imaginable. We got a preview of what this level of warming would look like in the Paleocene-Eocene Thermal Maximum and the Permian die-off. In the later, extinction rates reached 90%.

  4. Rick C says:

    Did the Wall Street bailout eat our green program recovery?

  5. Rick says:

    there is no green program. there never was. the only program the governments have is the appearance of prosperity.

    they throw out some crumbs to the greens to get their votes, but there is no program beyond looking just a little greener than the other guy.

    nothing is going to get done.

  6. Ronald says:

    There’s a question that is sometimes asked of people. If you knew the planet and everybody was going to die in 24 hours and you couldn’t do anything about stopping it, would you want to know?

    A regular reader of this website and other global warming blogs would surely answer that question as yes.

    Obama has been called a ‘Messiah,’ maybe he can do some good. Okay, maybe that was from detractors and political opponents of his.

    But tipping points are weird things. Who would have predicted 2 months ago that we would have the weird world wide stock market and financial problems that we have had. Some of the smartest and well informed people, Treasury Sec. and Federal Reserve chairman seemingly didn’t. We’re doing stuff in finance that we never could have predicted would be happening.

    Can the same thing happen with Global Warming acceptance and realization? Possibly not. But possibly yes. From my state, we may be electing a writer and preformer from Saturday Night Live, Al Franken, as our US senator (He’s a little ahead in an election of what was Paul Wellstone’s senate seat.) Maybe he can have some affect. The Democrats might have 57 senate seats, if not more. That might do some good.

    But if there is a real change, it would require doing things better and differently than they are happening now. But change does happen all the time. Just getting discouraged won’t do any good.

  7. paulm says:

    By adaptation I mean we have to try to start planing a way forward to the survive catastrophe, which is looking more and more certain.

    The future is going to be a very chaotic with a massive break down of civilly.

    Hopefully, we can start formulating a survival strategy now that we have the luxury of relatively peace and a not so panic stricken global environment.

    By golly, if you think the misery has not arrived have a look at Haiti, Cuba and the US Gulf coast, which I am willing to bet will be having disasters like this year every couple of years on average now!

    Is there going to be any adaption by those in the Hurricane basin? Will New Orleans will be abandoned – yes!

  8. David B. Benson says:

    For about one trillion dollars per year wee can permanently remove, by olivine mineralization, somewhat more CO2 than is added to the atmosphere by human activities.

    In the long term the price will come down.

  9. jorleh says:

    In Finland half of the country (the country 337 000 km2) is peatland. Or was. Practically 75 % is left nowadays of the whole. But the process is going on. We even burn the peat in a large scale.

  10. llewelly says:

    Ronald:

    There’s a question that is sometimes asked of people. If you knew the planet and everybody was going to die in 24 hours and you couldn’t do anything about stopping it, would you want to know?
    A regular reader of this website and other global warming blogs would surely answer that question as yes.

    It will probably be at least a decade or two before global warming causes severe problems for most Americans. It will be at least a century – probably more – before global warming kills the majority of its victims. The timescale of your hypothetical threat could not be more different from the timescale of global warming. Further – there are things that can be done to greatly reduce the severity of global warming (and in almost any conceivable AGW scenario, more CO2 emissions will always make things worse), and to adapt to what can’t be prevented. Finally – it is very unlikely that that AGW will kill everyone – even Lovelock considers that unlikely.

    AGW differs so much from your hypothetical threat that an interest in AGW is unlikely to predict an interest in your threat.

    But tipping points are weird things. Who would have predicted 2 months ago that we would have the weird world wide stock market and financial problems that we have had.

    Read Nassim Nicholas Taleb’s book The Black Swan . He predicted these problems at least as far back as 2003. (Although the book is mostly about other things.) He is not the only one, by far. And in 1999, when the laws that had kept investment banks separate from deposit banks, and the laws that had limited leverage, established after the 1929 market crash, were repealed, several liberal economics professors predicted there would be a housing bubble, a credit bubble, and, in about 10 years, they said, the collapse of many banks and lending agencies. That was a predicted disaster, but since respecting those predictions would have interfered with making tons of money, many influential people chose not to listen, chose to defame those who predicted a credit bubble, those who predicted worldwide financial problems, and so forth.

    Some of the smartest and well informed people, Treasury Sec. and Federal Reserve chairman seemingly didn’t.

    They stood to make a ton of money if the predictions of disaster were wrong. And when the predictions of the disaster turned out to be right, $700 billion was robbed and looted from taxpayers in order to bail them out.

  11. llewelly says:

    Ronald:
    Let me be more clear: the ‘smartest and well informed people, Treasury Sec. and Federal Reserve chairman’, the bond investors, and so forth, did not need to beleive the warnings they recieved, because they knew they would be able to abuse their wealth and political power to protect themselves from the disasters they caused, shifting the damage to others.

    Many of the fossil fuel company executives, and many of the AGW-denying politicians, feel exactly that way about global warming.

  12. Dano says:

    There is no adaptation without mitigation. There is no mitigation without adaptation.

    Best,

    D

    [JR: The first sentence is absolutely true — absent very robust mitigation efforts, adaptation is a meaningless term for what humanity will go through. The second sentence is really only true in an incidental sense. Some climate change is inevitable and hence some adaptation is inevitable. But again, if we were really really serious about mitigation, adaptation would be almost incidental.]

  13. Dano says:

    [RE subsequent comment to my comment above]

    Agreed to a point, Joe, but we will have to adapt our society and societal norms (e.g. rigorous conservation, closing the manufacturing loop) on our way toward mitigation.

    IOW: we will have to rethink the way we do things, which is adapting our society to be more thrifty, less wasteful, etc.

    Keep up the good work, sir.

    Best,

    D

  14. David B. Benson says:

    I suspect this is more alarming than the tundra. For peat outgassing appears to be a major component of

    http://en.wikipedia.org/wiki/Paleocene-Eocene_Thermal_Maximum