Thursday, July 30, 2009

Burning ice: impending danger

Russian permafrost offers up both hope and danger in this warming world.

It is a great preservation medium, not of fossils so much as DNA from unfossilised specimens (with tissue that hasn't degenerated and been replaced by seeping rock). Such finds, unfortunately, would only go back through the last few ice ages, up to about 700,000 years versus 65 million years for the dinosaur extinction.

But there is also a vast store of carbon fuel trapped within the permafrost, in a form known as methane clathrate: molecules of methane trapped within ice crystals. The tone of a recent New Scientist article was thrilled with the possibilities for this potential energy source, but strangely muted about the danger to the planet: it will accelerate global warming on release - methane being far stronger a greenhouse gas than carbon dioxide.

Clathrates are a delicate form of methane: if gas is extracted or gets loose, pressure can destabilise neighbouring crystals for a chain reaction: a "methane burp" that in releasing vast amounts of greenhouse gas, can also generate landslides and tsunamis.

There are three possible eventualities: permafrost clethrates are released as the planet warms, the deposits are exploited for fuel, or they stay in the ground. Perversely, if the planet warms and they are to be released anyway, it's better to use the fuel. On the one hand, methane molecules warm the atmosphere at 20 times the rate of carbon dioxide molecules. On the other hand, burning methane generates only half as much carbon dioxide as burning coal.

Therein lies the reason for the article's gleeful tone. We should be restructuring away from fossil fuels, but if the planet warms as expected, the methane gets released anyway.

You can read the full article here. Unfortunately it doesn't include the photos of burning ice from the print version. Spectacular - but deadly.

Whether or not extraction takes place depends on whether our energy and environment plans are fully evolved by the time extraction becomes fully viable. Will the burp happen anyway by now? The odds are not good.

No comments: