(Image source: Arctic Weather Maps)
During a murder investigation, sometimes you find traces of smoke from a gun fired in relation to the crime. In other cases, sometimes you find the gun itself. Even more rarely, do you find a smoking gun dropped at a still fresh crime scene. Such was the case with the Arctic today.
The crime scene: another anomalous Arctic heat wave. The suspect: human caused climate change. The accessory: Arctic amplification. The smoking gun: major methane emission in the Arctic.
Yesterday, I reported that a large Arctic heat wave had settled over Siberia, once again setting off tundra fires. The heat wave was so intense that it pushed temperatures in a range of 77 to 86 degrees all the way to the shores of the Arctic Ocean even as it caused numerous massive blazes to emerge both on open tundra and throughout Siberia’s boreal forests. Atmospheric conditions — a Jet Stream mangled by human caused climate change and a large heat dome had enabled the formation of this heat wave.
But now we find something even more ominous than evidence that human global warming is moving the Jet Stream about all while pushing polar amplification into such a high gear that the terms ‘Arctic Heat Wave’ and ‘Tundra Fire’ have now become common meteorological parlance. And that thing is a large and disturbing methane pulse.
(Image source: Methane Tracker)
On July 21-23, a large methane emission in which numerous sources caused atmospheric spikes to greater than 1950 parts per billion flared over a wide region of Arctic Russia and the Kara Sea. This event was so massive that an area of about 500 x 500 miles was nearly completely filled with these higher readings even as a much broader region, stretching about 2,000 miles in length and about 800 miles at its widest, experienced scores of large pulses. You can see a visual representation of these emissions in yellow on the image above, provided by Methane Tracker which compiles data provided by NASA’s Aqua Satellite.
As noted above, this major event coincided with a large Arctic heat wave and numerous tundra fires that raged throughout the region. Another unprecedented occurrence in a summer of strange weather and mangled climate.
Conditions in Context
Average global methane levels are currently around 1830 parts per billion (Mauna Loa surface data). This level, about 1130 parts per billion higher than the pre-industrial average of 700 parts per billion represents an additional global warming forcing equal to at least 28% of the added CO2 forcing provided by humans. It has long been a concern among scientists that the Arctic environment, as it is forced to warm by human-caused climate change, would emit an additional significant volume of methane from carbon stocks locked in tundra and in methane stores sequestered on the sea bed. Since methane has between 25 and 105 times the heating potential of CO2, the possible added additional warming is quite substantial.
In the 2000s, a number of Arctic researchers found disturbing evidence of methane emissions coming directly from the Arctic environment. In 2013, NASA began its CARVE mission to more clearly define the Arctic’s response to human-caused warming. Its preliminary research has found methane plumes as large as 150 miles across.
Overall, the Arctic environment is already clearly adding its own methane to the global mix. We can see this in local Arctic methane measurements that average around 1900 parts per billion and above in many Arctic locations. These readings are about 70 parts per billion above the global average. This week’s large methane pulse where a broad region experienced methane levels of 1950 to 1980 parts per billion is yet more evidence that the Arctic is beginning to provide a dangerous and troubling amplifying feedback to the already break-neck pace of human warming. In total, around 2,500 gigatons of methane are thought to be locked in carbon stores both in the Arctic tundra and in hydrates (frozen methane and water) on the Arctic Ocean floor.
Though a dangerous and troubling addition to a human-caused warming that is already changing the world’s weather in harmful and damaging ways, this particular methane pulse is not yet evidence of runaway global warming. In a runaway, Arctic methane emissions would likely exceed 500 megatons per year, which would be enough to raise global levels by about 150 parts per billion or more annually. Such a runaway would be a global nightmare requiring an unprecedented human response if Earth’s life support systems were to be preserved in any rough corollary to what we enjoy today. Though such an event is probably still low-risk (but perhaps as high as 10-20 percent), it cannot be entirely ruled out due to the speed and violence at which human greenhouse gas emissions are altering Earth systems.
So the prudent course would be for a rapid response as if such an event were imminent. The reason is that a runaway methane emission in the Arctic would cause severe and untold damage and harm.
To this point, Peter Wadhams is warning that about 50 gigatons of methane are at risk of rapidly destabilizing should the Arctic sea ice melt in the next two years. The region in which these methane stores are locked is the East Siberian Arctic Shelf, a shallow sea that is very vulnerable to rapid warming and methane release. Wadhams notes:
The loss of sea ice leads to seabed warming, which leads to offshore permafrost melt , which leads to methane release, which leads to enhanced warming, which leads to even more rapid uncovering of seabed. If a large release has not occurred by 2016 the danger will be continuously increasing. It is thought that at 2-3C of global warming, which means 6-8C of Arctic warming, methane release from permafrost on land will be greatly increased.
Those who understand Arctic seabed geology and the oceanography of water column warming from ice retreat do not say that this is a low probability event. I think one should trust those who know about a subject rather than those who don’t. As far as I’m concerned, the experts in this area are the people who have been actively working on the seabed conditions in the East Siberian Sea in summer during the past few summers where the ice cover has disappeared and the water has warmed. The rapid disappearance of offshore permafrost through water heating is a unique phenomenon, so clearly no “expert” would have found a mechanism elsewhere to compare with this.
Perhaps, equally troubling, is that large regions of permafrost are now also thawing. In the Hudson Bay region, an area that saw unprecedented heat, dry conditions and wildfires this year, permafrost temperatures have risen by .45 degrees Celsius. Peter Kershaw, an adjunct professor of earth sciences at the University of Alberta, who was in Churchill recently on a research project noted:
“It’s a big concern and so far not well-quantified. That organic material is being made available for decomposition. It’s out of the freezer and sitting on the counter.”
Though most climate scientists do not currently believe that such a rapid release of methane is possible over such a short period, we do have to ask ourselves — what if Wadhams and others like him are right? In such a case we could see a catastrophic warming of up to 5 degrees C by 2050, far beyond anything mainstream models or paleoclimate would suggest. But the human rate of climate forcing that is now more than ten times anything seen during the geological record puts us in a context that is entirely out of previous reckoning. So these warnings by Wadhams should be listened to, heeded, and taken into account. (Hat Tip to commenter Colorado Bob for the head’s up on these articles).
More likely, however, is that a combination of methane release from the tundra and the ocean floor and a loss of albedo (reflectivity) due to ice sheet loss will result in an effective doubling or more of the initial human greenhouse gas forcing over the coming decades and centuries. Such a response is still very dangerous in that it risks locking in, long term, already damaging changes to the world’s environments. Should the Earth System fully respond to the 400 ppm CO2 and 1830 ppb methane we’ve already achieved through our emissions , we can expect at least a 3 degree Celsius global temperature increase and long-term sea level rise of between 25 and 75 feet. Such changes would severely damage both human infrastructure and the environments upon which human-based agriculture depend for its now vast food production. In addition, a 24% increase in the hydrological cycle and a number of destabilizing changes to the world’s weather systems would cause severe added damage.
A rapid Earth Systems feedback response risks these changes at current greenhouse gas levels. And since we are now seeing both methane release and ice sheet response, a level of these feedbacks are already in play, showing a far greater risk than initial forecasts indicated. Further greenhouse gas emissions risk even more damaging potentials, possibly locking in ever-greater consequences. For this reason, any global policy that does not seek to fully mitigate such new and over-riding risks by planning a complete phase out of carbon emissions is an unconscionable policy to open the door to immeasurable harm to human lives and the living systems of our world upon which we depend.
These first methane burps are a warning for us to act now, before our capacity to act is seriously degraded and before events start to spiral beyond the point of rational control. We have had other warnings which we have, so far, mostly ignored. And though the responses by the Obama Administration and World Bank to de-fund new coal plants are encouraging, we should redouble our efforts now, lest we enter an age of bitter regret as the consequences of our carbon emission form a trap that is difficult or impossible to escape.