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Earth Stats Science

Carbon-Emitting Soil Could Speed Global Warming, Warns 26-Year Study (theguardian.com) 203

An anonymous reader quote the Guardian: Warming soil releases more carbon into the atmosphere than previously thought, suggesting a potentially disastrous feedback mechanism whereby increases in global temperatures will trigger massive new carbon releases in a cycle that may be impossible to break... The 26-year study is one of the biggest of its kind, and is a groundbreaking addition to our scant knowledge of exactly how warming will affect natural systems. Potential feedback loops, or tipping points, have long been suspected to exist by scientists, and there is some evidence for them in the geological record. What appears to happen is that once warming reaches a certain point, these natural biological factors kick in and can lead to a runaway, and potentially unstoppable, increase in warming...

In the Science study, researchers examined plots of soil in the Harvard Forest in Massachusetts, a mixed hardwood forest in the U.S. They experimented by heating some of the plots with underground cables to 5C above normal levels, leaving others as a control. The long-term study revealed that in the first 10 years there was a strong increase in the carbon released from the heated plots, then a period of about seven years when the carbon release abated. But after this second calmer period, which the scientists attribute to the adjustment of the soil microbes to the warmer conditions, the release of carbon resumed its upward path. From 1991, when the experiment began, the plots subjected to 5C warming lost about 17% of the carbon that had been stored in the top 60cm of the soil, where the greatest concentration of organic matter is to be found...

Lead scientist Jerry Melillo, points out that currently 10 billion metric tons of carbon gets released into the atmosphere every year, but "The world's soils contain about 3,500 billion tons of carbon. If a significant amount of that is added to the atmosphere, due to microbial activity, that will accelerate the global warming process. Once this self-reinforcing feedback begins, there is no easy way to turn it off. There is no switch to flip."

Carbon-Emitting Soil Could Speed Global Warming, Warns 26-Year Study

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  • Ecology Always Wins (Score:5, Informative)

    by Jzanu ( 668651 ) on Monday October 09, 2017 @03:52AM (#55334317)
    Global warming effects the habitability of every region for every organism, bacterial included. Before denialists complain on economic costs they must recognize the second layer of economics impacts from damage to the base agrarian sector that powers all of the economy. Humans require food to live, to use and to make everything else. We face quick changes that disrupt our existing transportation and market networks that distribute these resources, as well reduction in total yields. That damage and the cost of that damage dwarf all complaints about the costs of responding, through limits and changes in production techniques, and through transition to alternative sources of fuels and electricity.
    • by Anonymous Coward on Monday October 09, 2017 @07:32AM (#55334745)

      As I've been saying for over a decade: The fundamental issue with CC is that it invalidates the underlying assumptions of almost everything we build (or have built) or do. E.g. Is this a good place to build this power plant? Sure -- we can ALWAYS use water from the nearby river to cool it. And that's true, right up to the point when that river dries up or the water in it is too hot to be used for cooling. In the last 10 to 15 years there have been many examples in the US and the EU of thermoelectric power plants being throttled back or shut down completely for months over cooling water issues.

      Similarly, there are places in the SE US that use large municipal wells for drinking water. The problem is, rising sea levels are making salt water intrude into those wells, making them impossible to use without adding desalination plants.

      And yes, the potential impacts to agriculture and the basic biosphere are nightmarish.

      But what the hell -- let's all go out and buy ever bigger gas guzzlers and McMansions, because we're so confident that the impacts of CC won't hit during our lifetimes.

    • Gaia always wins (Score:5, Informative)

      by Latent Heat ( 558884 ) on Monday October 09, 2017 @09:32AM (#55335137)

      The Carbon Cycle is well understood. Of the CO2 emitted by human activity, half of that ends up in the atmosphere, the other half ends up in sinks. Half of that half goes into the ocean and the remaining half of that half goes into the soil.

      The reservoir capacity of the ocean is vast, orders of magnitude greater than the atmosphere. What prevents all of the CO2 from diffusing into the ocean is 1) the equilibrium of atmospheric and ocean CO2 follows a non-linear roughly 10th-power relationship owing to the chain of chemical reactions by which CO2 is "dissolved" (rather chemically bonded into soluble carbonates) and 2) there is a finite rate of mixing of the surface ocean layer with the deep layer. This model of the ocean along with some assumptions regarding the cycling of carbon between the atmosphere and the soils on land gives an accurate trace of the increase in atmospheric CO2 concentration from about 290 ppm at the dawn of the Industrial Revolution to over 400 ppm today. It also predicts the carbon isotope concentrations along with the seemingly short lifetime of CO2 in the atmosphere from the rapid extinction of radioactive C14 from atmospheric H-bomb testing that (mostly) ended in the mid 1960s -- this has to do with the non-linear absorption of CO2 by the ocean, which exchanges CO2 molecules at a high rate but resists requires greater changes in atmospheric partial pressure of CO2 to shift the chemical equilibrium. This may seem counter to intuition, but this is well understood P-Chem.

      Even though only half of the CO2 emitted by humans ends up in the atmosphere on account of the sinks, just about all of the increase in CO2 is the fault of humans. That is, unless there is a natural source of thermally stimulated emission of CO2 that needs to be taken into account.

      It is perhaps not widely known, but there is a large fluctuation in the year-to-year increase in atmospheric CO2. The fluctuation is of comparable magnitude as the human contribution that is believed to be much more steady -- we have boom and bust cycles in industrial output, but the variations are not quite that much.

      You may not have heard of this fluctuation, but NOAA's Carbon Cycle Guru Pieter Tans certainly knows about it. He attributes it to the effect of temperature changes on the rotting of fallen leaves and other litter in the tropical rainforests. He claims that the leaves that fall are very quickly rotted away, releasing most of their carbon back as CO2 into the atmosphere. His claim is that owing to the rapid decay of dead plant matter under tropical conditions, the reservoir is small. It accounts for the correlation between temperature and increase in atmospheric CO2 (called "net emissions), only occurring over short time windows. This correlation exists over longer time scales, but matters get fuzzy because human CO2 has ramped up over a time of gradual warming.

      Were you to believe Pieter Tans (yes, believe as much of this is based on modeling assumptions), there is minimal effect of decades-long increase in atmospheric temperature in driving CO2 emissions from the soil -- the decades-long increase is all attributed to the decades long gradual increase in industrial emissions with minimal contribution from warming of soils. Were you to regard NOAA's top Carbon Cycle dude as wrong, that increasing temperature drives a positive feedback of CO2 emissions over longer times than the year-to-year fluctuations seen in the atmospheric CO2 "Keeling curve", which TFA does, you would have already seen the effect on atmospheric CO2 because the climate has indeed been warming for most of the 20th century -- it has been warming, has it not, that is, unless you are a Climate Change Denier?

      If contra-Pieter Tans Head of the Carbon Cycle Section at NOAA the long term temperature trend is stimulating CO2 emissions from the soil in a positive feedback, there must be a countervailing negative feedback in the form of a commensurately higher absorption of CO2 by plants, an absorption that is sens

    • by doug141 ( 863552 ) on Monday October 09, 2017 @09:33AM (#55335145)

      Before denialists complain on economic costs they must recognize...

      Stop right there. I think you do not understand denial. Climate deniers deny the very thing you say they must recognize. They refuse to acknowledge the danger. Consider the Fuck That Gator [youtube.com] man.

    • complain on economic costs

      That is an often repeated assumption that going 'green' is going to cost a lot of money. There is zero evidence for it, but there is evidence for the opposite. Wind and solar energy is now cheaper than energy derived from coal. And that is not even adding on all the external costs of dirty fossil fuels (health impacts, foreign wars, climate change, etc).

  • Ban Soil! (Score:4, Insightful)

    by mentil ( 1748130 ) on Monday October 09, 2017 @04:21AM (#55334375)

    Ok banning it might not work. I say we tax possession of soil, maybe with a carbon credit system. Fallback plan: take all of this 'soil' and bury it deep, preferably under tons of dirt. As any politician knows, burying things takes care of them once and for all. /s

  • by wisebabo ( 638845 ) on Monday October 09, 2017 @05:36AM (#55334509) Journal

    I'm impressed by the fact that 26 years ago, some scientists put underground cables to warm the soil 5C and kept it that way for 26 years.

    I'm glad somebody even thought of this that long ago, it was (for most people) not on their radar. Who knows what other studies were proposed and were denied because of the political climate from the (Bush) administration. Then again, maybe it was funded by the university. Go Hahvahd!

    To the deniers: If we agree on nothing else can we at least agree on continuing to fund well planned scientific studies on the climate? If you really think there is no truth to this then you should be all for it, all the data is public and in fact you can run the studies yourselves! I've always thought that the TRUTH may come from people you completely disagree with.

    It would be a crime if due to the political winds/lobbyists these studies were denied, it's like an ostrich sticking its head into the ground (do they really do that?). It's would be like how federal studies into the links between gun ownership and gun violence is PROHIBITED or how the federal government isn't allowed to even negotiate for lower drug prices (despite being a huge buyer, through medicare/medicaid).

    Two things are crippling America: poor basic education in some parts of America due to widely uneven funding based on local communities resources (kinda defeats the idea of giving the next generation a fair chance). The other is legalized corruption by allowing unlimited corporate donations to politicians; for example this has resulted in American health care costs being more than twice that of the next country in the entire world! (With worse outcomes)

    • by Anonymous Coward on Monday October 09, 2017 @06:41AM (#55334647)

      To the deniers: If we agree on nothing else can we at least agree on continuing to fund well planned scientific studies on the climate?

      I have it under good authority that the science is settled. No further need for funding.

    • by dcw3 ( 649211 )

      Living in one of the best funded school districts in the nation (Fairfax Co., VA), I'll tell you that the schools still beg parents for supplies while he school system wastes millions on bullshit. Sorry, but no, there is such a thing as overfunding, and nobody is being a good shepherd of our tax dollars...property tax on my 4 bedroom is over $10k! There was nothing special about the education that my daughter received here that made it better than what I received in the public schools of Detroit. When yo

      • by jcr ( 53032 )

        I went to high school in Fairfax county, and I got a major shock on my first day of 9th grade when I realized that there were kids around me who couldn't even read out loud at a normal speaking pace.

        We sure as hell aren't getting what we pay for when it comes to public schooling.

        -jcr

    • by jcr ( 53032 )

      poor basic education in some parts of America due to widely uneven funding

      Nope. Funding is not the problem. The problem is incompetence protected from competition by politicians who want NEA money.

      -jcr

  • by Salgak1 ( 20136 ) <salgak@speak e a s y.net> on Monday October 09, 2017 @06:17AM (#55334599) Homepage

    Pave the Earth.

    One People.

    One Planet.

    One Sheet of Asphalt.

    (and yes, this *****IS***** sarcasm. . . )

  • Hmmm, I wonder... "conventional wisdom" has been that all of the paving humanity has been doing has created heat islands that are increasing localized global warming. But given this research, I am left to wonder: is there an offset? Clearly I'd think that paving or building over large plots of arid land would certainly squelch this CO2 emission. Of course, there is the carbon cost of the manufacture/construction to consider, but have we perhaps been abating something we didn't even know existed (or, at least, know was a significant CO2 source)? It would seem to me the next logical step for this group would be to pave or concrete over part of one of their experimental plots, accounting for the CO2 "cost" in doing so, and compare. I hate to see all the parking lots and acre-sized warehouses that are overtaking the lush green in my area, but...

    (Also, causes me to ponder fictional planets like Coruscant or Trantor.)

    • by dcw3 ( 649211 )

      localized global warming

      Is that like military intelligence, or hot water heater?

    • "conventional wisdom" has been that all of the paving humanity has been doing has created heat islands that are increasing localized global warming. But given this research, I am left to wonder: is there an offset? Clearly I'd think that paving or building over large plots of arid land would certainly squelch this CO2 emission.

      What would cause you to imagine that? Consider the case of housing built on landfill; gas escapes the ground. Pavement looks solid, and when it's new it might be (depending on the composition) but it rapidly cracks with use and with the natural settling of the land. Also, it comes in strips, and the land beneath it is porous, so gases can reasonably escape around it. However, being dark in color it does contribute substantially to soil warming, meaning that it actually exacerbates the problem.

      (Also, causes me to ponder fictional planets like Coruscant or Trantor.)

      Covering the e

    • Warm soil means faster plant growth. Trees sequester carbon.
      Planting trees is labor intensive. Scatter seeds and wait. It's not as if there's a shortage of seeds; many varieties of trees produce tens of thousands of seeds annually.
  • Remember this scary shit?

    https://en.wikipedia.org/wiki/... [wikipedia.org]

    I wonder if there could be any other "guns" we don't know about. Ah the joys of running an unintentional, unplanned geoengineering experiment on your only habitable planet.

  • take all the carbon, keep as much as need, box the rest up and shoot it into space. jobs a goodun, get trump on it.
    • Nah, shooting it into space takes too much work.

      Just build a wall around it, and make the Carbon pay for it.

  • We've already banned humans (evil carbon producers), just ban soil.

    Kevin Costner says if we wait long enough, the soil problem will take care of itself.
  • Everybody needs to react impulsively to this news and call for a ban on this stuff.

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