Is Climate Change Awakening a Methane Monster? July 28, 2014

Posts will be thinning out in coming days. I’ll be flying tomorrow to meet Dr. Jason Box, Dark Snow Project Chief Scientist, in Copenhagen. From there, we’ll hop to Kangerlussuaq, Greenland, and up to the ice sheet for the following 2 weeks or so. I’ll be checking in and posting till we jump to the ice.

Dr Box just sent me his latest blog post, something he had to look into that’s been keeping him awake nights. The methane studies covered in the video above relate mainly to methane from thawing permafrost on land. Dr. Box’s piece below looks into some more recent developments in the study of undersea methane deposits – the sleeping dragon of climate change. Note this is territory fraught with controversy, as the data from these remote areas is thin. But the stakes are very, very high.

Dr. Jason Box’s Meltfactor blog:

Using a vast and credible set of climate data and physics, James Hansen’s Storms of My Grandchildren makes the case that humans are on track to allow oceanic and atmospheric heating to reach a level triggering the release of vast additional carbon stores locked in shallow sea gas hydrates and/or from the ground in the Arctic. 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, eventually tenured, on micro and mesoscale meteorology and instrumentation, Hansen’s warnings should be met with an aggressive atmospheric decarbonization program. We have been too long now on a trajectory pointed at an unmanageable climate calamity. If we don’t get atmospheric carbon down, we will probably trigger the release of these vast carbon stores, dooming our kids’ futures to a hothouse Earth. That’s a tough statement to read when your worry budget is already full. 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 survey of the problem and what data we have. Also invited, Dr. Peter Wadhams pitched ”The cost to society of a methane outbreak from the East Siberian shelf”, completely off the fence, citing costs to humanity measured in trillions of $. The 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…

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? Well, unfortunately, the Tiksi record is too short to deduce a trend. A longer set of methane concentrations data from Alert, far northern Canada, adds 8% increase in methane concentrations to the more than 250% increase due to human activity since industrialism began ~1750. Green symbols on the charts indicate extreme positive outliers. A reasonable hypothesis for the outliers marked below by me with dragon breath? 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. ” For the moment, let’s leave the outliers question open and move on to an argument I’ve got that the measurements are not near enough the centers of gas release action to get at the awakening dragon question. We’d like a sampling station right over the shallow, methane-charged, and now mostly ice free [in summer] Laptev and East Siberian Seas. Of course, that’s much easier said than done. Before talking about measurements over the centers of action… 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 the very unsurprising “retrieval error is larger in the high northern latitude regions“. They 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. Comparisons between IASI retrievals with near-surface direct measurements would establish the uncertainties we would be faced with and build the case for using the IASI retrievals to represent wide areas not benefiting from direct sampling. More digging yielded some accuracy findings for IASI from Yurganov et al. (AGU poster 2012) 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, one 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 team states “At several places, the methane “bubbles“ even rose to the ocean surface. What’s more, results of preliminary analyses of seawater samples pointed towards levels of dissolved methane 10-50 times higher than background levels. And it’s not just the Swedes who are on this question. NASA is too. What’s the take home message, if you ask me? Because elevated atmospheric carbon from fossil fuel burning is the trigger mechanism. 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.