It’s essential that policymakers begin to seriously consider the possibility of a substantial permafrost carbon feedback to global warming. If they don’t, I suspect that down the road we’ll all be looking at the 2°C threshold in our rear-view mirror. — Robert Max Holmes
Unraveling the global warming puzzle is simple at its face, complex when you pierce the surface.
We know that burning fossil fuels, that the activity of mining coal, fracking for gas, and drilling for oil all result in dangerous greenhouse gas emissions. We know that the vast majority of these warming gasses are coming from fossil fuel based sources. We know that, now, the burning and mining and fracking and drilling have pushed atmospheric CO2 above 405 parts per million and the global concentration of all CO2 equivalent gasses to an amazing 485 parts per million CO2e (levels not seen in at least 15 million years). And we know that the heat re-radiated by these gasses has warmed the world by about 1 C above 1880s levels — forcing weather patterns to change, seas to rise, ocean health to decline, and setting off a wave of die offs in the animal world while increasing the near-term risk of hunger, spreading tropical disease, and mass displacement in the human world.
(Heat added to the Earth’s atmosphere by fossil fuel emitted gasses like CO2 and Methane are measured in watts per meter squared. A yardstick known as radiative forcing [RF]. In the above graph by IPCC, we can see the estimated levels of radiative forcing from each greenhouse gas and total net human heat forcing upon the Earth atmosphere as of 2011. It’s a measure that may also need to start adding in the RF of feedback greenhouse gasses as the 21st Century progresses. Image source: RealClimate.)
We know many of the names of these other gasses — methane, nitrous oxide, and chlorofluorocarbon. And some of the others — like sulfur hexaflouride — many of us haven’t yet heard of. But the big name, the primary warming agent, is carbon dioxide — responsible on its own for the majority of the overall heat forcing currently. A gas so important to long term warming that NASA has called it ‘the thermostat that controls Earth’s temperature.’
All this is pretty simple and straightforward. But it’s when we start looking at what are called amplifying feedbacks — the Earth System Sensitivity responses to human forced warming — that things really start to get dicey. And wrapped up in the Earth System Sensitivity equation is methane — a greenhouse gas with the ability to strongly influence global temperatures over rather short time-frames.
Methane Spikes to Over 3,000 parts per Billion
On February 20th, for about 12 hours, the NOAA METOP measure recorded a major atmospheric methane spike in the range of 3,096 parts per billion at 20,000 feet in altitude. This was the first time that any measure had recorded such a high methane spike and the first time any measure had exceeded the 3,000 parts per billion threshold. For context, just two years ago, a methane spike in the range of 2,660 parts per billion would have been significant. Now, we’re getting peak readings that are more than 400 parts per billion higher than that previous maximum threshold.
(METOP showed a record 3,096 parts per billion atmospheric methane spike on February 20 of 2016. Thus far, this was the largest such spike ever recorded in the NOAA measure. One that far exceeded a global atmospheric average of around 1830 parts per billion. Image source: NOAA/METOP.)
It’s a pretty ominous signal — especially when you consider the fact that global atmospheric methane averages are in the range of 1830 parts per billion. The recent major spike was about 1170 parts per billion higher. In other words — a pretty extraordinary excession. It’s evidence that the methane sources of the world are growing more vigorous in their output. And when you consider the fact that methane — on a molecule-by-molecule comparison to CO2 — traps about 80 times more heat over the decadal timescale, large additions of methane on top of an already dangerous CO2 forcing is certainly cause for some concern. An issue that may further speed the already rapid pace of human-forced warming such that we become at risk of hitting the 1.5 C and 2 C thresholds sooner than expected. Outcomes we should urgently be working to avoid — by cutting the human-based emission as rapidly as possible at this time.
The Usual Suspects — Fossil Fuel Based Activity
Perhaps still more concerning is the fact that we really don’t know exactly where this significant methane spike is coming from.
We do, however, have a long list of usual suspects. The first, of course, would be from any number of very large and dangerous fossil fuel emission sources. China, with its massive methane belching coal mines, gas infrastructure, and dirty coal burning facilities would be a prime suspect. Mongolia, where equally sprawling coal and gas facilities operate is another likely hot spot. Russia — with its vast and leaky oil and gas fields. The Middle East — which is choked with fossil fuel infrastructure. Europe — where many of Russia’s pipelines terminate and where many nations burn a high-methane brown coal. And the United States — where the geologically destructive practice of fracking has now also recently and greatly increased methane emissions.
Unusual Suspects — Permafrost and Clathrate Warmed by Fossil Fuel Emissions
Looking at the very low resolution METOP graphic above, we find a number of methane hot spots around the globe. And many of these hot spots do coincide with our usual suspects list. But others are well outside the range we would typically expect. Far up in the north. Over the tundra and the Arctic Ocean where few major fossil fuel burning or extraction facilities now exist. There, somewhat ironically, great piles of permafrost spreading over millions of square miles and sometimes mounding up as thick as two miles are thawing due a greenhouse gas heat forcing from fossil fuel burning often happening hundreds or thousands of miles away. This thawing permafrost is filled with organic material. And when freed of its icy prison it is exposed to the world’s elements and microbes. These forces then go to work turning the organic carbon in that permafrost into carbon dioxide and methane.
This is rather bad news. In total, more than 1,300 billion tons of carbon are locked away in the permafrost soils. And carbon emissions from permafrost make an already bad heat forcing coming from fossil fuel burning even worse.
(Atmospheric methane levels as recorded by various reporting stations and global monitors have been rising more rapidly during recent years. In the Arctic, atmospheric readings have tended to remain above the global average — an indication that local emissions are generating an overburden for the region. Image source: NOAA ESRL.)
But if all the human emissions and potential permafrost emissions weren’t bad enough, we have one more major carbon source in the Arctic to consider — methane hydrate. A controversial potential methane release source to be certain. But a very large one that we would be remiss to ignore. Due to the fact that the Arctic has remained very cold overall for the past 3 million years of long ice ages and brief interglacials, this massive store of carbon has been given the opportunity to build up within the relatively shallow and now swiftly warming Arctic Ocean waters and even beneath large sections of now-thawing permafrost. Much of this carbon is in the form of the frozen ice-methane called hydrate. And as the Arctic Ocean warms and sea ice recedes to expose blue ocean to the heating of the sun’s rays for the first time in hundreds of thousands of years, there is concern among some scientists that a not insignificant amount of that submerged frozen methane will release, pass the ocean-atmosphere or thawing permafrost boundary, and add more heat forcing to the world’s atmosphere. The shallow sea of the East Siberian Arctic Shelf has been identified by some to contain as much as 500 billion tons of carbon in the form of frozen methane. And a fossil fueled heating of the Earth may be just now risking amplifying feedback level releases from this large clathrate store along with a number of other very large stores scattered all across the Arctic Ocean basin and on throughout the global ocean system.
A Clearer Picture? Or One Far More Complex?
So who among all the various suspects — usual and unusual — may be responsible for the record methane spike now showing up in the METOP measure?
Before we attempt to answer this question, let’s pull in another methane graphic — this one from the Copernicus Observatory:
(The February 25 Copenicus methane graphic tracking surface methane readings gives a higher resolution indication of surface methane readings than the NOAA METOP measure. This second measure provides some confirmation of an Arctic methane overburden even as spike sources from human emissions become more readily apparent. Omnious spikes also apparently come from wildfires in the tropics and from regions in the Arctic near Yamal, Russia, Northern Scandinavia, the Barents and Kara seas. Image source: The Copernicus Observatory.)
Here we can see the range of surface methane readings according to Copernicus. A higher resolution image that may provide us with a better idea of the point-source location for daily global methane spikes. Here we see that the major methane sources are predominantly China, Russia, the Middle East, Europe, the United States, India, Indonesia, Fires in Africa and the Amazon, and, finally, the Arctic.
Though the Copernicus measure doesn’t show the same level of Arctic overburden as what has tended to show up in the METOP measure, it’s a confirmation that something in the near Arctic environment is generating local spikes in above 1940 parts per billion for large regions of this sensitive zone.
The Copernicus measure, as noted above, also shows that the human spikes are quite intense, remaining the dominant source of methane emissions globally despite a continued disturbing overburden in the Arctic. Spikes in Africa, the Amazon, and Indonesia also indicate that declining rain forests and related fires in these tropical zones are also probably providing an amplifying feedback to the overall human emission.
Given this month’s spikes and the overall disposition of surface methane readings around the globe, it does appear that the large human base methane emission is being enhanced by feedbacks from local emissions from carbon stores both in the tropics and in the Arctic. This enhancement signal, though somewhat smaller than the fossil fuel related signal in some measures, is concerning and hints that Robert Max Holmes’ warning at the top may be all-too-relevant. For Earth System feedbacks to massive and irresponsible fossil fuel emissions appear to already be starting to complicate our picture of a warming Earth.
Hat Tip to Griffin