Over the past few months, reporting stations around the Arctic have shown a ramping rate of atmospheric methane accumulation. The curves in the graphs are steepening, hinting at a growing release of methane from a warming Arctic environment.
* * * *
(Alert, Canada methane graph shows atmospheric methane increases in the range of 20 parts per billion in just one year. This rate of increase is 2-3 times the global average for the past five years. A skyrocketing rate of increase. Image source: NOAA ESRL.)
A Massive Thawing Carbon Store in the Far North
The science is pretty settled. There’s a massive store of ancient carbon now thawing in the Arctic.
In the land-based permafrost alone, this store is in the range of 1.3 billion tons — or nearly double the volume in the atmosphere right now. Arctic Ocean methane hydrates in the East Siberian Arctic Shelf add another 500 billion tons. A rather vulnerable store that does not include hundreds of billions of additional tons of carbon in the deeper methane hydrates around the Arctic in places like the Gakkel Ridge, in the Deep Waters off Svalbard, or in the Nares Strait. Massive carbon stores of high global warming potential gas locked in frozen ground or in ice structure upon or beneath the sea bed.
But now human beings — through fossil fuel emissions — are dumping heat trapping gasses into the atmosphere at an unprecedented rate. These gasses are most efficient at trapping heat in the colder, darker regions of the world. And, due to a combination of massive Northern Hemisphere burning, and release from the Arctic carbon stores themselves, the highest concentrations of greenhouse gasses can be found exactly where they are needed least — in the world’s far northern zones .
(The Arctic consistently shows an overburden of methane gas — both at the ground and upper levels of the atmosphere as seen in this METOP graphic from May 29. Such an overburden is but one of many proxy indicators of a ramping rate of release.)
This accumulation and overburden of heat trapping gasses is causing the Arctic to rapidly warm. A rate of warming (now at half a degree Celsius per decade for most regions) that is providing a heat forcing pushing the ancient carbon stores to release. A heat forcing now greater than at any time in the past 150,000 years (and likely more due to the fact that the Eemian Arctic was rather cool overall). A heat forcing rapidly ramping toward at least a range not seen since major glaciation began in the Northern Hemisphere 2-3 million years ago.
The problem for science, then, is two-fold. First, as oceans warm and permafrost thaws, how rapidly will the carbon stores release? And, second, how much of that carbon store will release as CO2, and how much will release as methane? From the point of view of global warming, both CO2 and Methane emissions feedback is a bad outcome of human-forced warming. But methane, which has a global warming potential of between 25 and 120 times CO2 over human-relevant timescales, has a real potential to make an already bad human heating of the Earth System much, much worse.
(Image source via Science 2.0.)
Most Arctic Reporting Stations Show Rapid Ramping of Methane Gas Accumulation
For this reason, monitoring methane gas accumulation in the Arctic is a key feature of global climate change risk analysis. If the Arctic shows a spiking rate of methane accumulation, then the carbon stores are more susceptible to rapid release of potent heat trapping gasses and we are facing a high urgency situation in need of rapid global response.
Over the past decade, the Arctic has shown numerous isolated or regional spikes to very high methane levels with an overall continued accumulation within the atmosphere. The Arctic also displayed a major overburden of both methane and CO2 — proxy indications of local carbon store feedbacks already ongoing on a minor-to-moderate scale. This combination of overburden and spikes provided a troubling context, especially when adding in observations of methane store release through thermokarst lakes and, later, blow-holes in locations like Yamal, Russia. But up until last year, we had not seen a third, and more troubling, indicator — the ramping rates of atmospheric methane accumulation that would be an early warning that the Arctic carbon store was indeed starting to blow its stack.
But now, that signal is starting to show up at almost every Arctic reporting station. A steepening curve in the Arctic atmospheric methane graphs. A signal we really, really don’t want to be bearing witness to:
(Major reporting stations from Svalbard to Barrow show a ramping atmospheric methane accumulation [Click on individual images to expand]. It’s a signal that is yet one more indicator of an amplifying methane and greenhouse gas feedback to human warming now going on in the Arctic. Images provided by NOAA ESRL.)
Now, it seems, at the very least, we are witnessing a spike in Arctic atmospheric methane accumulation. Let’s hope it’s just a spike and not the start of another ugly exponential curve associated with human-forced atmospheric warming. But if we are witnessing the early ramp of such a curve, we should be clear that we are now in the context of a worst-case climate change scenario.
Hot-Button Topic of Critical Importance
For years, conjecture over the possible rate of Arctic Methane release in a human-warmed Arctic has been the source of extreme scientific and media-based controversy. Major oil companies have used the issue as an excuse to continue fossil fuel burning (irresponsibly spreading the meme — ‘we’re screwed, so we may as well just keep burning anyway’). Major climate scientists and related media outlets have sought to tamp down concern over large-scale methane release by issuing articles with titles like ‘Apocalypse Not’ with many generally insisting that there is practically zero likelihood of a large-scale methane release or major amplifying feedback. Meanwhile, the observational studies have continued to indicate risk of at least moderate and possibly strong methane feedback in an age of rapid human heating of the Arctic environment (studies like this recent paper which observed microbes tripling the rate of methane gas release in thermokarst lakes as a response to Arctic temperature increase.) Finally, a group of very concerned observational scientists like Natalia Shakhova, Igor Simeletov and Peter Wadhams have warned that a large-scale methane release is likely imminent and begs a major response from the global community (sadly, many of these proposed responses have come in the form of geo-engineering — methods which are far less likely to succeed and far more likely to generate unforeseen and highly disruptive consequences than simple cessation of human fossil fuel emission and a transition to carbon-negative civilizations).
(Mauna Loa methane measure through June 1, 2015 shows that lower Latitude regions are also starting to follow a ramping rate of increase. Image source: NOAA ESRL.)
All this controversy aside, what we observe now is the following:
- Arctic methane and CO2 overburden — proxy indication of environmental release.
- Increasing rates of release, indications of increasing release, or possibly increasing release from single sources such as thermokarst lakes, peat bogs, wildfires, and sea bed hydrates and submerged tundra.
- A multiplication of observed or discovered methane release sources — thermokarst lakes, methane blow holes, wildfires etc.
- A ramping rate of atmospheric methane accumulation at reporting stations throughout the Arctic (most but not all stations).
- A ramping rate of atmospheric methane accumulation from global proxy monitors like Mauna Loa and in the global atmospheric average.
Together, these observations represent a troubling trend that, should it continue, will be proceeding along or near a worst-case climate sensitivity track. As such, these new ramping rates of increase in Arctic atmospheric monitors are a very unfortunate indicator.