Tuesday, 30 September 2014

The clathrate gun

When it Comes to The Arctic Methane Monster, What We Don’t Know Really Could Kill Us — NASA Model Study Shows Very High Carbon Release Uncertainty

(Can we save humanity from the greatest threat ever? Must-watch video highlights the risks and uncertainties of catastrophic methane release from the Arctic environment.)

29 September, 2014

After millions of years of ice ages, the Arctic has become a vast repository of fossil carbon.

Over the millennia, layer after layer of carbon-based biological material has been locked away in the frozen soil of the Arctic tundras and sea beds. Some of these stores have simply become entombed within the ice. Others, already turned to methane through the slow fluxes of time, underlay the frozen ground and the chilly Arctic sea-bed floor as a kind of fire ice.
An unstable, flammable, and explosive substance called clathrate.
The stores themselves are massive — containing between 2,000 to 3,000 billion tons or more of carbon. Likely more than five times the amount of carbon humans have already emitted into the atmosphere over the past 150 years. An amount that has already likely locked in about 1.8 C of warming short term and 3.6 C worth of warming long-term.
But a thawing Arctic could set off a chain of events leading to far worse warming to come.
In a cold, ice-age world these carbon stores are no threat. Like a sleeping dragon, they remained dormant in the world’s chill zones — unable to break the seal of the ice. But in a world that humans are forcing to rapidly warm through a pace of greenhouse gas emission at least 6 times faster than at any time in Earth’s billions-years history, we risk a major release of this monstrous carbon stockpile.
A Matter of Methane Feedback
We really don’t know how much heat forcing is required to set off a runaway release of this monstrous pile of carbon. But we’ve already warmed the world by at least 0.8 degrees Celsius and many Arctic researchers believe that just 1.5 degrees Celsius global warming is enough to thaw all the Arctic’s tundra.
Such a thaw would certainly expose the massive tundra carbon store to the elements and to microbial action. Increasing an already significant release of Arctic carbon and greatly contributing to the human heating of the Earth’s atmosphere and oceans through greenhouse gas emissions.

Dragon's Breath Jason Box
(In a recent article on his Meltfactor blog, Dr. Jason Box questions whether local anomalies in Arctic methane data involve mini methane outbursts set off by human-caused heating. Dr. Box also, appropriately questioned whether such releases were signs of a potential and larger release due to the human heat forcing of the Arctic environment. Dr. Box, in a manner similar to our own investigation of the Arctic Methane Monster, metaphorically labels these outbursts ‘dragon’s breath.’ Image source: Meltfactor.)
A few years ago, a group of 41 Arctic researchers suggested that even if we stopped emitting greenhouse gasses rapidly, the Arctic release of carbon would equal about 10 percent of human annual human emissions and would continue for a long time into the future. More ominously, these researchers noted that a failure to rapidly draw down human carbon emissions would result in an annual Arctic release of equivalent to 35% or more of the human emission — putting the world on track for a runaway warming scenario.

But the matter of Arctic carbon release is anything but simple or easy to understand. For a significant portion — possibly as much 1/3 to 1/2 of the Arctic carbon store could release as methane. And methane, on very short time scales, is a very potent greenhouse gas. Over the course of 20 years, methane has a global warming potential 86 times that of a similar volume of CO2. If even a very small portion of the Arctic carbon store were to release as methane over a relatively short period — 1, 5, 10 or 50 gigatons out of a total store measuring in the thousands of gigatons — it could greatly exaggerate the already powerful human warming underway or, in the worst case, set off a runaway heating event similar to that of the great Permian and PETM extinctions.
A Poorly Understood Risk
Unhelpfully, there is nowhere near enough direct observation of the Arctic environment to pin down the current rate of carbon release or the likely increase in release rates over the past few decades. We have studies that show more methane emitting from tundra lakes, for example. We have the Semiletov and Shakhova expeditions to the Arctic Ocean which keep providing higher and higher estimates of the methane emissions coming from plumes on the sea floors of the Laptev and East Siberian Seas. We have studies that show increasing CO2 and methane release from the vast carbon stores of Yedoma’s frozen tundra in Siberia. And we have the more disturbing instances of explosive methane outbursts — likely from rapidly thawing clathrates beneath the permafrost — in the Yamal region of Russia this year that resulted in a dramatic cratering of Siberian tundra.
Arctic Methane Overburden
(Large sea-bed methane release ongoing? The Arctic continues to show a very significant overburden of Methane — hinting at larger releases of methane from the Arctic environment. Last year during October, methane readings over the Gakkel Ridge spiked to 2662 parts per billion — or more than 800 parts per billion above the global average — before diffusing into the atmosphere. The above image shows methane over the same region spiking to over 2,400 parts per billion on September 16 of 2014. Link: Arctic News.)

But these studies and instances focus only on subsections of the Arctic. And, in much the way several blind men investigating the various parts of an elephant might disagree on the overall shape of the beast, we have a similar problem with understanding the total shape of the threat posed by Arctic methane and carbon release.

Dr. David Archer, who has developed various model essays of potential Arctic and sea bed methane release claims that there is essentially zero cause for concern for a large-scale methane release this century. A number of Arctic researchers disagree with the chief of these being Peter WadhamsDr Semiletov and Dr Shakhova who all seem very concerned about the potential for a large-scale release soon. A middle ground is populated by a number of researchers like Carolyn Ruppel and Sue Natali from the Woods Hole observatory. These researchers are rationally calling for more data on an issue that is all-too-poorly understood in the science.
NASA’s CARVE Finds Models in Disagreement Over Arctic Carbon Release
This current lack of broader understanding and scientific consensus on the issue of potential Arctic and Earth Systems response to a growing human heating of the atmosphere and ocean was highlighted in last week’s report by NASA’s CARVE study.
The study — aimed at monitoring Arctic Carbon emissions — ran a number of global climate models to try and determine how much carbon is currently being released from the Arctic environment. The study didn’t try to pin down future release scenarios. It just aimed at trying to establish a base line for emissions as they stand now. An understanding required to provide any clear assessment of where Arctic carbon emissions may be going in the future.
The researchers plugged the current spotty Arctic carbon emissions data into 40 global climate models and the models dutifully spit out results that were all across the board. In essence, the models confirmed what we risk analysts already knew — there’s not enough information currently available to provide a clear understanding of potential Arctic carbon release scenarios much less pin down how much carbon is currently being emitted.
From last week’s Science Daily Report:
How much carbon is leaving its thawing soil and adding to Earth’s greenhouse effect? …
A new study conducted as part of NASA’s Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) shows just how much work still needs to be done to reach a conclusion on this and other basic questions about the region where global warming is hitting hardest.
Lead author Josh Fisher of NASA’s Jet Propulsion Laboratory, Pasadena, California, analyzed 40 computer models of the amounts and flows of carbon in the Alaskan Arctic and boreal ecosystems. His team found wide disagreement among the models, highlighting the urgent need for more measurements from the region…
We all knew there were big uncertainties in our understanding, and we wanted to quantify their extent,” said Fisher. That extent proved to be greater than almost anyone expected. “The results were shocking to most people,” he said.
Cause For Rapid Reduction in Greenhouse Gas Emissions Now
(Ocean methane seeps like these recently discovered vents off the US East Coast and those Discovered in the Laptev Sea by the SWERUS C3 expedition are almost always more numerous and energetic than expected — a likely result of increasing human heat forcing. Such releases almost always include destabilized clathrate stores. Image source: Nature-Geoscience.)
It will take years for scientists to more certainly pin down the risk posed by Arctic Carbon and methane release. A risk that now wraps within it the potential to set off a new Permian type hothouse extinction during the coming 1 to 3 centuries. A risk that, altogether, is likely the most dire risk we’ve ever faced as a species.
As such, we can’t wait for absolute certainty on the scope of that risk. Whether there’s enough sensitivity to set off a large Arctic carbon release at 1.5 C or 6 C warming is moot — because we know that continuing to burn fossil fuels eventually gets us there sooner or later.
So as we continue to research what may well be the greatest environmental threat we’ve ever faced it is entirely prudent to begin a rapid reduction of global carbon emissions with a goal to hit zero carbon and net negative carbon emissions as soon as possible. The risks are simply too great to continue to delay action.
Hat Tip to Apneaman
Hat Tip to Colorado Bob

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