Sunday, March 28, 2010

Climate Point of No Return May Already Be Upon Us

Sub-sea methane in the Eastern Siberia Arctic Shelf area is already bubbling to the surface at a rate 200 x faster than in the world's other oceans. According to a recent study, this release of sub-ocean floor methane reservoirs, due to destabilization of melting permafrost ice caps on the seabed, could represent the initial signals of a climate Armageddon that has been feared.       

There is an area in the Arctic, just north of eastern Siberia, where vast amounts of methane gas have been stored for eons, locked into place by permafrost on the floor of the Arctic Ocean. It has long been presumed that frigid Arctic seawater would keep the permafrost frozen in place.

Now, according to a study published in Science Daily, scientists have discovered that the permafrost "cover" has become unstable and that unprecedented amounts of the gas, which has a 30 times more potent greenhouse effect than Co2, are already being released.

According to the scientists, led by Natalia Shakhova and Igor Semiletov of the University of Alaska Fairbanks, methane is already escaping from the Siberian Arctic at a rate of approx. 7 teragrams, roughly 1 million tons, per year.   The concentration of methane in the Arctic has already reached 1.85 parts per million, a level unprecedented in 400,000 years.

None of the current climate models even include the feedback from methane being released from the permafrost covered tundra, let alone this methane from below the ocean floor.

 According to the Science Daily article, "Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming."

If these findings are confirmed, the next step, I suppose, will be to determine the extent of the deterioration of the ice on the seabed. Given that this one patch of ocean is already expelling as much methane as the rest of the world's oceans combined, I would say the chances are very strong that significant perforation of the ice cap on the sea floor has already occurred. If so, I don't know what could realistically be done to even slightly mitigate the effects of this. Could millions of collectors that would collect the methane either by a chemical or mechanical process be suspended in the sea somehow? Could the ice melting be slowed? I can't even imagine...


The difficult thing here is that the aspect of this equation that has been possibly human-triggered, that is the warming of ocean currents and the melting of the ice on the seabed, would be very difficult to reverse by any estimation. As temperatures in the Arctic have increased more than elsewhere on the planet, and have already resulted in the melting of almost all the multi-year ice in the Arctic, the chances of getting anything to cool down in the Arctic in the near future just seem extremely remote.

The size of the East Siberian Arctic Shelf is approx 2 million sq. kilometers, which represents about .5% of the Earth's ocean surface. 

2 comments:

The Mound of Sound said...

There's a balanced discussion of the methane issue at realclimate.org. It's not that it isn't a problem, it's a problem of perspective.

Offroad Artist said...

Thanks for mentioning that. The article does well at drawing the big picture. I think the point is that if the ice on the ocean floor is starting to melt - it is unlikely to melt slowly and this methane problem could become a game changer in a hurry. Perhaps it has not started to break down yet. That would be a welcome finding.