Sounding the methane alarm

A team of scientists confirms that sea-bottom and surface waters of the East Siberian Arctic Shelf are “super-saturated” with Methane (CH4) gas and “out-gassing” this potent GHG to the Atmosphere.

Large quantities of carbon (C) and methane (CH4)– typically in the form of methyl hydrate (or methyl clathrate)– are trapped in ocean sediments the world over. Through natural erosion of sediments, shifting of the ocean floor covering, and/or from pressure cracking, bubbles of the gas often escape and rise up through the water column.

In the deeper seas and oceans, this natural gas venting to the atmosphere (“out-gassing”) is largely constrained due to the fact that, as the rises through the water column, much of it combines with oxygen and forms other, less potent molecules. Also, in colder seas, sub-sea permafrost acts as a “lid” to contain much of the buried carbon.

The ESAS is the largest shallow sea in the world. Despite this, the ESAS generates a methane flux ten times that of the deeper ocean.Something amiss. Yet anoter pointer to how little we know about the planet, and hence, how wrong our predictions could be!

Many climatologist are concerned that Arctic warming–which is greater than predicted by several degrees C so far this century–will accelerate the thawing of sub-sea permafrost and thus also the release of CH4. Methane, though shorter-lived in the atmosphere than CO2, is a far more potent GHG than CO2, in terms of its heat-trapping capability.

Plug the methane

In focusing on carbon dioxide, the world is overlooking a more dangerous candidate for warming – methane. A recent EPA study showed vast amounts of methane escape from landfills, livestock, coal mines and oil and gas wells, pipelines and storage tanks. The emissions are in many cases avoidable — at a profit.

The new total, again just from gas wells, has the climate-warming power in a year of the carbon dioxide emitted by eight million cars.

Changing practices are capturing growing amounts of landfill and coal-mine methane. Experts at the Environmental Protection Agency acknowledged publicly for the first time that the flow from standard practices at gas wells, not including leaky valves and the like, is at least 12 times higher than the longstanding agency estimate.
And E.P.A. officials say the total could be many times higher than that.

Companies working to cut flows of the gas from oil storage tanks say that source of emissions is similarly grossly underestimated.

Methane, besides having 25 times the climate impact of carbon dioxide when the gases are compared over a 100-year period, is a fuel and chemical feedstock. So capping the leaks brings in two-sided advantage! Not just about belching cows!

The team at MIT that looked at climate benefits of cutting methane emissions says that reducing methane is a cheap, fast solution to the short term problem. Not to forget carbon dioxide which is still far ahead by virtue of its sources.