Feedback Loops in the Arctic

By BJ Bjornson

A report being published today notes that one of those nasty little feedback mechanisms the Climate Change crowd has been warning everybody about has already been having an effect.

There is plenty of ice at the top of the planet after last winter, but a new report indicates it may not be there for long.

The report to be published today in the journal Nature includes new satellite data and concludes the excess warming between 1989 and 2008 was tied primarily to reduction in sea ice cover. The more the ice melted, the more the upper ocean warmed and the more heat was then released back into the atmosphere feeding the warming trend.

"The findings reinforce suggestions that strong positive ice-temperature feedbacks have emerged in the Arctic, increasing the chances of further rapid warming and sea ice loss," says the report.

The rise in Arctic air temperature in the last decade has been twice the global average, with a record-breaking ice retreat in the summer of 2007. This so-called Arctic amplification has been attributed to various forces, including changes in atmospheric and ocean circulation, cloud cover and water vapour.

Last month, some rapid ice formation led to a great deal of crowing by the climate pseudo-sceptics, since it meant the maximum ice coverage reached this winter was greater than the lowest ever recorded. It was still well below average for the last 30 years though, which gives you some idea of how desperate the pseudo-sceptics are in grasping at such thin straws to make their case.

�Thin� being the operative word in all of that, as in the late-forming ice is quite thin and won�t last long once things warm up. This is a large part of the reason scientists don�t use the maximum ice coverage very often but focus on the yearly minimums. The minimums allow you to get a measure of how much multi-year ice the Arctic has, the kind of ice that has some staying power during the warm months and has become increasingly rare over the last decade.

In any case, it seems increasingly clear that we have likely passed the point of stopping climate change from happening and should be more worried about adaptation and mitigation, not that the pseudo-sceptics won�t be fighting that tooth and nail as well.