Using a vast and credible set of climate measurements and physics, James Hansen’s Storms of My Grandchildren makes the case that humans overloading the atmosphere with carbon would eventually trigger the release of vast additional carbon stores locked in shallow sea gas hydrates and from Arctic tundra.
In my professional opinion as a climatologist with more than 70 externally reviewed scientific publications, after 12 years of university education focused on atmospheric and oceanic science, and followed by 10 years of university lecturing on micro and mesoscale meteorology theory and instrumentation, Hansen’s warnings should be met with an aggressive atmospheric decarbonization program. We have been too long on a trajectory pointed at an unmanageable climate calamity; runaway climate heating. If we don’t get atmospheric carbon down and cool the Arctic, the climate physics and recent observations tell me we will probably trigger the release of these vast carbon stores, dooming our kids’ to a hothouse Earth. That’s a tough statement to read when your worry budget is already full as most of ours is.
December 2013, I found myself in a packed room at the world’s largest science meeting, the AGU fall meeting. The session: “Cutting-Edge Challenges in Climate”. Invited speaker Dr. Lori Bruhwiler presented “Arctic Permafrost and Carbon Climate Feedbacks” - a cautious, objective, and science-only [politics-free] survey of the Arctic carbon issue and what data we have. Also invited, Dr. Peter Wadhams pitched “The cost to society of a methane outbreak from the East Siberian shelf”, off the fence, citing costs to humanity measured in trillions of $. My take home from the session was well paraphrased by Bruhwiler, citing a sparse observational network, concluding ‘we just can’t say much yet’. That was then…
The global network of greenhouse gas sampling stations as per NOAA
Clearly, considering the vastness of the Arctic, the network of ground-based observing stations does appear sparse, with a solitary station representing Siberia, at Tiksi, you’re left thinking that governments should do more to keep their finger on this pulse. On the pulse side, however, the measurements happening at Tiksi [and other sites in the network such as Alert and Pt. Barrow northern Alaska], I can tell you, are really high end; with BSRN radiometers, eddy covariance gas fluxes, gas flask sampling, etc., impressive and not inexpensive. What do these data tell us?
- A 30 year methane data series from Alert, far northern Canada, 30 year, includes an 8% increase in methane. This is the most recent 8% of the more than 250% humans have elevated methane since industrialism began year 1750 or so. The Tiksi record started recently is too short to deduce a trend. But it includes, like the other records in this network,
- Methane records from this network include occasional spikes. Green symbols on the charts below indicate these extreme positive outliers. A reasonable hypothesis for the outliers marked below by me with dragon breath? [I had these labled WTF? ] would be: extreme outlying positive anomalies represent high methane concentration plumes emanating from tundra and/or oceanic sources. Another reasonable hypothesis would be: extreme outlying positive anomalies represent observational errors. What NOAA states: the outliers “are thought to be not indicative of background conditions, and represent poorly mixed air masses influenced by local or regional anthropogenic sources or strong local biospheric sources or sinks. ” Fair enough. But, the dragon breath hypothesis has me losing sleep.
same spikes evident in 32 years of Pt. Barrow, Alaska data. here, I don’t bother to overlay the dragon breath?s.
While we don’t have permanent measurements floating over the oceanic centers of action, for example over the Eastern Siberian shallow continental shelf, we do have satellite data from the Infrared Atmospheric Sounding Interferometer (IASI) on board the Eumetsat Polar System (EPS) Metop-A Satellite. And as I know from installing/maintaing Arctic ground measurements and publishing articles assessing the quality of satellite-derived retrievals from the Arctic, most recently here, validation studies are needed. So, it’s good to find Xiong et al. (2013) who, using “596 methane vertical profiles from aircraft measurements by the HIAPER Pole-to-Pole Observations (HIPPO) program” find that the remotely sensed quantities are accurate and have a small (less than 2%) low bias. Yet, their assessment is for the part of the atmosphere well above the surface. Some accuracy findings for IASI over the Arctic are provided by the Yurganov et al. (AGU poster 2012) that concludes:
- IASI data can be used as qualitative indicator of the Arctic Ocean methane emission.
- Current methane growth in the Arctic, including 2012, is gradual.
- Methane emission from the Arctic shelf has a maximum in September-October. [when sea ice minimum occurs]
- Top-down emission estimates are difficult and may be very uncertain ( e. g., ± 100%)
- If a sudden venting (bubbling) of methane would happen due to intense hydrates destruction, IASI would be able to detect it near real-time
Now, a Sam Carana leads a group who have been blogging up a storm about methane estimates from the IASI sensor. Their messaging is alarming, connecting dots between methane maps they generate using IASI data and a number of rapidly changing Arctic climate elements: declining sea ice area, duration, volume; increasing air and sea surface temperature, wildfire.
My understanding was that the methane bubbles can’t or don’t make it to the surface, instead are converted to much less potent carbon dioxide before reaching the surface. Then, here’s what we hear from 4 days ago from a Swedish team now surveying the Laptev sea with a very high-end icebreaker, named for the main Norse god.
The Swedish team states “At several places, the methane “bubbles“ even rose to the ocean surface. That’s damn scary. Atmospheric methane release is a much bigger problem than atmospheric carbon dioxide release, since methane is ~20 times more powerful greenhouse gas. If as it seems, sea ice reduction is destabilizing the shallow Arctic Ocean continental shelf waters. Without the reflective cover, the ocean is taking on a lot more solar heating during the 24 h summer days, making it harder for the sea ice to reform, in a self compounding feedback process. Places like the Laptev and East Siberian seas, are shallow, and the water column can more easily be mixed by wind action than when sea ice cover was there. This new heating and mixing can be what unlocks the shallow sea gas hydrates, allowing the methane up to the surface.
The methane bubbles they filmed boiling up toward, even to the surface of the Arctic Ocean.
The story of methane bubbles coming to the surface is not actually that new. Here’s a 2011 pieceon the topic. Shakova et al (2013) suggest that: “significant quantities of methane are escaping the East Siberian Shelf as a result of the degradation of submarine permafrost over thousands of years. We suggest that bubbles and storms facilitate the flux of this methane to the overlying ocean and atmosphere, respectively
What’s the take home message, if you ask me? Because elevated atmospheric carbon from fossil fuel burning is the trigger mechanism poking the climate dragon. The trajectory we’re on is to awaken a runaway climate heating that will ravage global agricultural systems leading to mass famine, conflict. Sea level rise will be a small problem by comparison. We simply MUST lower atmospheric carbon emissions. This should start with limiting the burning of fossil fuels from conventional sources; chiefly coal, followed by tar sands [block the pipeline]; reduce fossil fuel use elsewhere for example in liquid transportation fuels; engage in a massive reforestation program to have side benefits of sustainable timber, reduced desertification, animal habitat, aquaculture; and redirect fossil fuel subsidies to renewable energy subsidies. This is an all hands on deck moment. We’re in the age of consequences.
There are still questions, of course, but the cautionary principle makes clear we have to keep this dragon in the ground.