There’s no avoiding it — climate change is a controversial subject; a threat that should unify us all that, due to reticence, denial, fear, and a basic lack of understanding, is instead often quite divisive. But among the subjects that stand out as real fodder for acidic controversy, the issue of methane feedbacks from the global climate system — the oceans, thawing permafrost, and especially the Arctic — is one of the worst. There’s a noted tendency to either downplay or overplay risks. Though this polarization is likely fed by the general mysteriousness and complexity of the subject, its potential existential nature also feeds into the heat that methane feedback-related discussions tend to draw.
It all makes one hope for improved discussion on the subject. Given the fact that catastrophic methane feedback appears unlikely (but would have a high overall impact if it did emerge), it’s probable that the subject will continue to generate a difficult conversation for as long as human-forced warming is an issue, and so long as the science continues to remain uncertain.
(The Copernicus Observatory shows surface methane hot spots in China, Africa, South America, the U.S., Canada, Europe, Russia and the Arctic. Note that generally high concentrations still tend to center over the Arctic. Meanwhile, the various hot spots seem to indicate major sources like fossil-fuel industry wildfires, wetlands, droughts, the Arctic Ocean and glacial and permafrost thaw. Also note that current readings indicate a serious rise in global methane concentrations, but not a spike that significantly exceeds peak 20th-century additions. It’s worth considering that, during recent years, expanded natural gas exploration and extraction through fracking has likely contributed a substantial new human methane source addition to the global atmosphere. Meanwhile, there is some concern that the Earth System may be starting to mildly feed back by bleeding additional carbon from warming lands, forests, oceans and permafrost.)
It’s not really a question of whether or not some scientists are concerned or if there is a risk, however ill-defined. Dr. James Hansen has often indicated that a strong methane feedback from the Arctic or world ocean system would be a climate nightmare that could well eliminate the time window to respond to prevent catastrophic warming. Methane and other carbon feedbacks are prime suspects for past hothouse event triggers — potentially playing a role in setting off events like the Permian-Triassic Extinction and/or greatly contributing to the loss of ocean health that was a key feature of these extinction events. Neil deGrasse Tyson alluded to this risk in his 2014 rerendering of the science series Cosmos.
Polar researchers, including those at the National Snow and Ice Data Center (NSIDC), often point to varying risks and potentials for methane feedback from numerous sources such as permafrost thaw. Others fear releases coming from seabed stores — claims that often meet stiff resistance from more established areas of the science. But given how close we are to locking in 2-degree-Celsius or greater amounts of warming this century, it doesn’t take a lot of carbon feedback, methane or otherwise, from the Earth System to generate a problem. Even a moderate feedback would cut the time necessary for carbon emissions draw-downs. It is for this reason that monitoring of the methane, and overall carbon feedback, situation is a necessary part of developing a comprehensive climate change situational awareness (which I have worked hard to develop here at this blog). Which is why, today, we are going to talk a little bit about a big methane spike appearing in the hourly readings near Barrow, Alaska.
Apparent Record Methane Spike in the Hourly Readings at Barrow
The graph tracks hourly methane readings at the data collection location for Barrow, Alaska. As shown, the recent (and unconfirmed) data set shows what appears to be a record methane spike for that location. Also note that big spikes appear in the hourly data at certain points many times since 2000, as is typical during this time of year. Most notably, a similar very large spike occurred in 2004, one that the recent 2016 spike just edges out.
Looking at the graph, there’s a lot that it doesn’t tell us. Firstly, what is the source of this methane spike? If the spike was an outlier with no periodicity it might indicate the potential for some kind of anomaly or human source. However, since seasonal spikes seem to show up in this graph, this hints that the current spike is environmental. In addition, since Alaska as a whole and Barrow in particular both recently experienced some of their warmest weather on record, there’s some reason to suspect that this added heat played a part in the 2016 spike. And, 2004 also saw a period of then-record warmth during summer in Alaska. So Alaska warming is in line as a suspect cause for the 2016 methane spike.
As anomalous spikes go, this one is pretty big — it apparently set a new hourly record methane reading around 2370 parts per billion for the recording station. But since this Barrow spike isn’t visibly part of some big regional methane plume and since the global monitors aren’t recording a big methane jump as well, we can be pretty certain that this particular spike, if confirmed, is a local and probable short-term issue, and not a sudden, huge methane release issue of global importance. However, it does represent another point in a context that seems to include some big local methane sources popping up in the Arctic environment and possibly indicating a larger, if comparatively moderate, regional feedback taking place in response to the warming and thawing ongoing there. (No consensus scientific study has yet fully confirmed such a preliminary observation, which is a threat analysis-based potential identification on my part.)
So, overall, something to add to the big pot of bubbling concerns — but nothing to light your hair on fire over yet.
Conditions in Context
During the 20th century, large-scale industrialization linked to fossil-fuel burning and extraction helped to drive rapid rates of atmospheric methane increase. These rates peaked during the late 1980s and early 1990s when global policy measures helped curtail methane leakage from fossil fuel infrastructure. According to NOAA, annual rates of global atmospheric methane increase peaked in 1991 at a 14.32 ppb yearly jump.
(Global methane is again hitting a rapid rate of rise. Though the Earth System appears to be providing some ominous rumblings that feedbacks may be on the way, the present spike is likely primarily due to increased fossil-fuel extraction activity, particularly due to fracking. Image source: NOAA.)
Such curtailments helped to produce a mid-1990s to mid-2000s plateau in the rate of atmospheric methane accumulation. Now, with the advent of fracking and with global warming appearing to generate a number of possible new methane sources (or amplify traditional sources) from the Earth System, rates of annual methane increase are again on the rise. In 2014 and 2015, annual increases hit 12.53 ppb (the third highest annual rate of increase in the NOAA record) and 10.07 ppb respectively (tenth highest). Preliminary reports show that 2016 appears to be on track to hit near 10 ppb worth of atmospheric increase.
As a result, it appears that fracking, primarily, and warming-related feedback (possibly secondarily) are contributing to annual rates of atmospheric methane increase that are comparable to peak periods of increase during the late 1980s and early 1990s. However, these rates of increase, though significantly adding a heat forcing that about equals one quarter to one third of the annual CO2 addition, show no current indication of a catastrophic rate of methane increase that would point toward the major environmental releases some have feared. As such, the greatest part of our ability to currently prevent further rising rates of atmospheric methane comes in the form of rapidly reducing all fossil fuel use and particularly to contain and reduce coal mining and oil and natural gas fracking. And if we do that, there will be less heat stress on the environmental methane stores and less overall long-term pressure for the kinds of feedbacks some of us have come to fear.
Hat tip to Griffin