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Friday, August 01, 2014

Methane Mega-Flares Threaten To Accelerate Global Warming

Ominous news about a new source of greenhouse gases comes from Icebreaker Oden, currently cruising the Arctic Ocean:
We are ‘sniffing’ methane. We see the bubbles on video from the camera … All analysis tells the signs. We are in a [methane] mega flare.

Chief scientist Örjan Gustafsson of the University of Stockholm writes:

So, what have we found in the first couple of days of methane-focused studies?
1) Our first observations of elevated methane levels, about ten times higher than in background seawater, were documented already as we climbed up the steep continental slope at stations in 500 and 250 meter depth. This was somewhat of a surprise. While there has been much speculation of the vulnerability of regular marine hydrates [frozen methane formed due to high pressure and low temperature] along the Arctic rim, very few actual observations of methane releases due to collapsing Arctic upper slope marine hydrates have been made. ¨
It has recently been documented that a tongue of relatively warm Atlantic water, with a core at depths of 200—600 meters may have warmed up some in recent years. As this Atlantic water, the last remnants of the Gulf Stream, propagates eastward along the upper slope of the East Siberian margin, our SWERUS-C3 program is hypothesizing that this heating may lead to destabilization of upper portion of the slope methane hydrates. This may be what we now for the first time are observing.
2) Using the mid-water sonar, we mapped out an area of several kilometers where bubbles were filling the water column from depths of 200 to 500 meters. During the preceding 48 hours we have performed station work in two areas on the shallow shelf with depths of 60-70m where we discovered over 100 new methane seep sites. SWERUS-C3 researchers have on earlier expeditions documented extensive venting of methane from the subsea system to the atmosphere over the East Siberian Arctic Shelf. On this Oden expedition we have gathered a strong team to assess these methane releases in greater detail than ever before to substantially improve our collective understanding of the methane sources and the functioning of the system. This is information that is crucial if we are to be able to provide scientific estimations of how these methane releases may develop in the future.

The Arctic Methane Emergency Group has been warning governments about the potential for a runaway greenhouse event due to methane:

While land and subsea permafrost thaws ever faster, methane could become the dominant climate forcing agent. Emissions threaten to break through the gigaton-per-year level within twenty years. AMEG has been continuing its research into the situation. A recent paper, co-authored by Peter Wadhams, a founder member of AMEG, has used the Stern Review economic model to show that the economic cost of a 50 megaton release of methane from the Arctic Ocean seabed will cost $60 trillion. Research in the East Siberian Arctic Shelf has suggested that such a vast release of methane was possible, and continued exponential increase of methane could, within 20 years, reach a level where methane dominated over CO2 in global warming. Some researchers warn of a 50 gigaton burst being possible “at any time”.