Good news: Methane hydrate breakdown unlikely to cause massive greenhouse gas release

From the US GEOLOGICAL SURVEY

Gas hydrate (white, ice-like material) under authigenic carbonate rock that is encrusted with deep-sea chemosynthetic mussels and other organisms on the seafloor of the northern Gulf of Mexico at 966 m (~3170 ft) water depth. Although gas hydrate that forms on the seafloor is not an important component of the global gas hydrate inventory, deposits such as these demonstrate that methane and other gases cross the seafloor and enter the ocean. CREDIT Photograph was taken by the Deep Discoverer remotely operated vehicle in April 2014 and is courtesy of the National Oceanic and Atmospheric Administration's Ocean Exploration and Research Program.

Gas hydrate (white, ice-like material) under authigenic carbonate rock that is encrusted with deep-sea chemosynthetic mussels and other organisms on the seafloor of the northern Gulf of Mexico at 966 m (~3170 ft) water depth. Although gas hydrate that forms on the seafloor is not an important component of the global gas hydrate inventory, deposits such as these demonstrate that methane and other gases cross the seafloor and enter the ocean. CREDIT Photograph was taken by the Deep Discoverer remotely operated vehicle in April 2014 and is courtesy of the National Oceanic and Atmospheric Administration’s Ocean Exploration and Research Program.

The breakdown of methane hydrates due to warming climate is unlikely to lead to massive amounts of methane being released to the atmosphere, according to a recent interpretive review of scientific literature performed by the U.S. Geological Survey and the University of Rochester.

Methane hydrate, which is also referred to as gas hydrate, is a naturally-occurring, ice-like form of methane and water that is stable within a narrow range of pressure and temperature conditions. These conditions are mostly found in undersea sediments at water depths greater than 1000 to 1650 ft and in and beneath permafrost (permanently frozen ground) at high latitudes. Methane hydrates are distinct from conventional natural gas, shale gas, and coalbed methane reservoirs and are not currently exploited for energy production, either in the United States or the rest of the world.

On a global scale, gas hydrate deposits store enormous amounts of methane at relatively shallow depths, making them particularly susceptible to the changes in temperature that accompany climate change. Methane itself is also a potent greenhouse gas, and some researchers have suggested that methane released by the breakdown of gas hydrate during past climate events may have exacerbated global warming.

The new review concludes that current warming of ocean waters is likely causing gas hydrate deposits to break down at some locations. However, not only are the annual emissions of methane to the ocean from degrading gas hydrates far smaller than greenhouse gas emissions to the atmosphere from human activities, but most of the methane released by gas hydrates never reaches the atmosphere. Instead, the methane often remains in the undersea sediments, dissolves in the ocean, or is converted to carbon dioxide by microbes in the sediments or water column.

The review pays particular attention to gas hydrates beneath the Arctic Ocean, where some studies have observed elevated rates of methane transfer between the ocean and the atmosphere. As noted by the authors, the methane being emitted to the atmosphere in the Arctic Ocean has not been directly traced to the breakdown of gas hydrate in response to recent climate change, nor as a consequence of longer-term warming since the end of the last Ice Age.

“Our review is the culmination of nearly a decade of original research by the USGS, my coauthor Professor John Kessler at the University of Rochester, and many other groups in the community,” said USGS geophysicist Carolyn Ruppel, who is the paper’s lead author and oversees the USGS Gas Hydrates Project. “After so many years spent determining where gas hydrates are breaking down and measuring methane flux at the sea-air interface, we suggest that conclusive evidence for release of hydrate-related methane to the atmosphere is lacking.”

Professor Kessler explains that, “Even where we do see slightly elevated emissions of methane at the sea-air interface, our research shows that this methane is rarely attributable to gas hydrate degradation.”

The review summarizes how much gas hydrate exists and where it occurs; identifies the technical challenges associated with determining whether atmospheric methane originates with gas hydrate breakdown; and examines the assumptions of the Intergovernmental Panels on Climate Change, which have typically attributed a small amount of annual atmospheric methane emissions to gas hydrate sources.

The review also systematically evaluates different environments to assess the susceptibility of gas hydrates at each location to warming climate and addresses the potential environmental impact of an accidental gas release associated with a hypothetical well producing methane from gas hydrate deposits.

Virginia Burkett, USGS Associate Director for Climate and Land Use Change, noted, “This review paper provides a truly comprehensive synthesis of the knowledge on the interaction of gas hydrates and climate during the contemporary period. The authors’ sober, data-driven analyses and conclusions challenge the popular perception that warming climate will lead to a catastrophic release of methane to the atmosphere as a result of gas hydrate breakdown.”

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The paper, “The Interaction of Climate Change and Methane Hydrates,” by C. Ruppel and J. Kessler, is published in Reviews of Geophysics and is available here. The USGS and University of Rochester research that contributed to the review was largely supported by the U.S. Department of Energy and the National Science Foundation.

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52 thoughts on “Good news: Methane hydrate breakdown unlikely to cause massive greenhouse gas release

  1. Another good example of how much we know we don’t know. We are helpless when it comes to estimating the contribution sources and quantities of atmospheric methane. Let alone predict the future.

    • We do know that CO2 and methane have about a five year half-life in the atmosphere and as methane is at one-400th of the concentration of CO2 in the atmosphere, it is a tempest in a teapot. Just another way to arm people who do not know the real facts.

      Even as “greenhouse gases”, these gases have no detectable effect during the day, as they are saturated and both absorbing and emitting IR radiation, and actively radiate IR out to space during the night. These gases serve to cool the climate. It is only fatally wrong “climate science” that has these “radiative gases” heating anything.

      • What we do know is that it has been warmer in the past, and we are still here, so methane might, just might, not be a problem. Ah ! The uses of observation.

  2. Although gas hydrate that forms on the seafloor is not an important component of the global gas hydrate inventory, deposits such as these demonstrate that methane and other gases cross the seafloor and enter the ocean.

    Translation please, someone. Where is this ‘seafloor’ of which they speak that is apparently not in the ocean?

      • Khwarizmi,That layer is populated with microbes which eat the natural
        gas, oxidizing it. It does not disappear, it just changes its form.

      • Yeah – it gets eaten, Jerry. The gas doesn’t make it all the way through the seafloor, precisely because it gets eaten. That was stated in the title of the paper I referenced. It only metaphorically “vanishes,” like food on your plate does when you eat. Not sure what your point was.

  3. Since natural gas perks up all around the world all the time.
    some is being released into the atmosphere continuously.

    Small releases are mans from habits, such as natural gas
    releases from rice paddies. The soil upon, which the paddies
    are built, owe its richness to the amount of the gas up welling
    through the soil which are normally oxidized, eaten, by microbes.
    when the soil is dry. When the paddies are flooded, the water
    forces the gasses to the surface quicker than the microbes
    can eat them, causing a “man made” release of natural gas

    For a major release to occur, a very large event is required,
    such as a meteorite or comet strike. The shock and vibration
    introduces mechanical heat to the earth,s core. This
    could release very large amounts of hydrates from their zone
    of stability.

    • Jerry

      Thanks for that. I have not seen anything in print about vibration releasing methane hydrates. The idea of mechanical heating, obviously, is an issue but I believe the temperature sensitivity is not that high. By that I mean the pressure is more important than the temperature. It is analogous to compressing LPG. If the LPG is heated, the higher tendency to boil is manifested, but if it is at 10 bars pressure it doesn’t turn to gas – the pressure is too high. LPG liquefies at 5 bars.

      It is not clear from the article what the suggested narrow pressure/temperature range is. It is because lower in the earth it is warmer, so the hydrates don’t form? If that is the case, then it makes sense to consider there is an upper elevation where there is just enough pressure to form, and a lower elevation where the temperature is not too high. In between, methane hydrates will form.

      The suggestion that ‘the warming oceans’ will release them is poppycock in my view because the warming is incredibly slow, if and where it is taking place. I understand there is a lot of such hydrate material off the NE coast of Japan over to Alaska. That is hardly a hotspot for ocean floor warming.

      I am happy to see that a careful, long study of the ‘issue’ shows that it isn’t one. Next crisis please.

  4. Perhaps this is the first of a continuing series of research findings that fall into line with the views of the current administration. (improves funding outlook).

    • Sad to say, I’m not sure this paper would have seen the light of day while Marcia McNutt was director of USGS. She was a disaster and very political.

      But the real point, as made by Adam_0625 below, is that methane simply doesn’t matter in the IR absorption game. Far too rare, and its absorption bands are largely overlapped by CO2 and water vapor

      Drives me nuts when clueless “climate reporters” repeat the fantasy that Methane is a “powerful greenhouse gas, 20X more powerful than CO2”

      Yeah, CH4 is also “able to leap tall buildings at a single bound!”

  5. Non-issue even if it does get released. The IR absorption bands for methane are few, narrow, and close to (if not already) saturated. Adding more methane has little if any energy to absorb. It, therefore, can contribute little, to any, to warming.

  6. A similar process to the rice paddy event occurs to a lesser extent in all
    rich upland soils. The natural gas up wells continuously, usually
    at a rate which the local culture can oxidize. Frozen soil can block
    oxidation or rain saturated soil can cause the natural gas to rise
    faster than it can be eaten by the microbes.

    The USEPA is confused by the finding of methane, actually natural
    gas, in the top soil, claiming that it is absorbed from the atmosphere.

    Their past methane budget has listed upland soil in the USA as
    a 30 tg per year sink. This means that they actually have no idea
    where the gasses come from.

    When methane hits the atmosphere, it rises.

  7. If warming led to release of methane hydrates that in turn caused warming then the climate could not have been stable enough to have prevented the runaway feedback from already happening.

    This was obviously a silly scare story. Most of us called it then. We are still calling it now that observations are finding the methods by which the feedback is prevented.

    But the scare story got a lot more press than the science. Some people will keep on believing it regardless of logic.

    • For some people, no amount of fact will be sufficient to counter deeply held beliefs. CAGW is a religion, pure and simple.

  8. Le Chatelier’s principle applies here. Since natural gas has always risen
    continuously after the earth’s internal fires were lit, events which caused
    a major release of gasses were corrected by microbes and oxidation in
    the atmosphere.

    Minor events such rising and falling sea levels are adjusted without much
    notice.

    For those who believe that ice cores are a reliable measure of CO2,
    past sea level changes would reflect in massive releases, and major
    spikes of CO2.

  9. Filed under
    “It isn’t happening now so it probably won’t ever happen”

    This is just another clear example of climate scientists failing on the ‘side of least drama’. Obviously, Arctic ocean temperatures have not changed significantly up to this point. However, there will be great changes in the Arctic over the next 3-7 years and then massive increases in warming after that. The way things stand, we won’t see a methane hydrate release until at least 2065 as the loss of Summer sea ice moves earlier and earlier in the melt season.

    Emissions of methane from melting permafrost and boreal peat will be growing much more rapidly before then.

    • You are assuming facts not in evidence. IE that current warming is caused by CO2 and not part of a natural cycle.
      Secondly actual science has already show that as permafrost melts, lichen and mosses consume all of the released methane and CO2.

    • “The way things stand, we won’t see a methane hydrate release until at least 2065”

      For some people, no amount of fact will be sufficient to counter deeply held beliefs. Useful tools will keep to their religion, no matter what happens.

  10. Virgina Burkett’s statement is far more straightforward than the conclusion of the study.

    Maybe we are seeing federal employees being freed from the constraints of the climate mafia – free speech at last?

  11. According to AGW theory, at the same time that the oceans are warming, they are also getting deeper because of melting ice.
    Wouldn’t the increased pressure compensate for the warming and as a result the methane would stay in it’s hydrate form?

    • Any methane that is released will disolve into the seawater, from which it will do one of three things:
      1. migrate to another site and resolidify
      2. be consumed by biota in the water
      3. migrate to the atmosphere, where it is rapidly oxidised.

  12. The atmosphere has been much warmer in the past, and according to the
    ice core CO2 reading, no spike in CO2, therefore, no spike in natural gas.

  13. The Trump effect is operating more rapidly than previously thought. It seems that we are about to find out the real ratio of political scienceyness to objective, empirical science. The old 97/3 has already swooned.

  14. Are those live mussels clinging to the overhanging crest of hydrate? I don’t think the methane has a chance to rise through the water column.

  15. Gary, at the “black smokers”, the base food is hydrocarbons. Microbes eat
    the natural gas and the mollusks are then fed.

  16. The USGS is 2-0 with this and the earlier release on the core data on corals and the AMO record. Real science takes time.

  17. OMG!!! It’s not worse than we thought! It’s not even as bad as we thought! It’s not even bad at all! This is really, really bad news! It’s a crisis! What are we going to frighten the peasants with now?

    Better add /sarc –

  18. @Steve Ta
    Methane Hydrate is found beneath old deep ice, as found under Greenland and under the Antarctic ice where the pressure is high enough for the formation of them. But also is lies beneath the ocean basins, the depth under the seafloor is deep enough they refer to the methane leaks gassing across/cross the seafloor. Methane also (I don’t know how they form though!) below Arctic permafrost and not a very great depth either. Lastly a measurable amount is found at/on the continental shelfs where is appears to lie on the surface. Apparently the amount of hydrate that is available in/on the continental shelves is very little compared to the other sources.

  19. The fear has been that methane release caused by thawing permafrost would trigger a runaway global warming event. But there is no real evidence that such an increase in greenhouse gases would actually cause any global warming. The AGW conjecture is based on a radiant greenhouse effect caused by LWIR absorbing gasses but such an effect has not been observed anywhere in the solar system including the Earth. It does not exist. There is no such happening in the paleoclimate record. For example, the Eemian was warmer than the current intergalcial period with higher sea levels and more ice cap melting yet runnaway global warming never occoured. If such runnaway global warming were possible then the so called greenhouse gas most likely to cause it would be H2O but it never has.

  20. Last night I saw “Catastrophe – The Permian Extinction” https://www.youtube.com/watch?v=HmeTCw5Xk1I .

    My favorite comment on it was “yeah … yeah … yeah … it was exactly like that …” .

    It had an obnoxious tone of certainty and blamed the second half of the catastrophe on the release of sea floor methane hydrates by a 5c warming — causing an additional 5c warming .

    Crispin somewhere commented that the methane containment was much more pressure than temperature sensitive , and just reading this post , my immediate desire was to see a temperature,pressure phase plot for the hydrates .

    • Can’t help with pressure sensitivity of hydrates. Permian uncertinties are staggering. This is what I get:

      What strikes me about the Permian extinction is the coincidence of extremely high temperatures with a volcanic hiatus and sea level low stand. Equally high temperatures coupled with enormous volcanism and a sea level high stand were no problem in the Cretaceous until the asteroid hit…

      What this says to me is that CO2, the second most prolific exhalation from volcanoes after water, is not implicated in the Permian temperature spike. CO2 and temperature in that time frame look like this:

  21. “the methane often remains in the undersea sediments, dissolves in the ocean, or is converted to carbon dioxide by microbes in the sediments or water column”

    Which means that it might interfere with the assumptions made about atmospheric oxygen depletion by fossil fuel combustion (methane oxidation uses twice as much oxygen per mole of CO2 produced compared to coal combustion). Of course this doesn’t really matter in the real world, but, given the relatively small scale of human carbon fluxes it adds an extra large dollop of uncertainty to the “carbon budget” calculations which the precious ones rely upon.

  22. This is another example of how post-modern science operates.
    You don’t actually have to do any research, nor do you have to formulate a hypothesis that you are going to test against the evidence. All you do is run a whole series of “scientific papers”, written by others, through a computer program which analyses what those papers are about & their conclusions. From the results of your computer program, you then write another paper explaining what you found.
    After that you find a magazine editor desperate for something to publish, & whoopee, your publication count has just gone up.

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