Has runaway Arctic warming already begun?

[gulfcoastliberal]

Runaway warming of the Arctic threatens to spread climate havoc across the globe in the coming decades, according to a new study by the environment group WWF. But has the process already begun? Climate scientists meeting at the World Climate Conference in Geneva, Switzerland, where the report was launched today, are in two minds.

Some reckon the WWF report may understate future events. The report's author, climate adviser Martin Sommerkorn, reckons 90 per cent of the Arctic's surface permafrost could be lost by 2100. But Jerry Meehl of the US government's National Center for Atmospheric Research at Boulder, Colorado, told the conference that unless humans curb their greenhouse gas emissions "there will be zero permafrost by 2100".

Melting permafrost is likely to release huge volumes of methane, accelerating global warming faster than previous predictions, according to many speakers at the conference. Fears of such releases prompted another US government agency, the National Oceanic and Atmospheric Administration (NOAA), this week to start regular research flights over Alaska, sniffing for methane.

Conversely, the WWF's headline-grabbing claim that the disappearance of Arctic sea ice during summer 2007 was a tipping point in Arctic warming may be wide of the mark. Vicky Pope, head of climate change advice at Britain's Met Office, said less ice disappeared in the summer of 2008. And that there had probably been even less melting there this year, though final reports will only come in over the next two weeks.

http://www.newscientist.com/article/dn17726-has-runaway-arctic-warming-already-begun.html?DCMP=OTC-rss&nsref=climate-change

[joshcryer]

1. IPCC AR5 is going to be one of the most pivotal, mind numbing reports in the history of science.

So much has happened by our continual release of 25+ billion tonnes of CO2 yearly, that even with the IPCC being *very conservative* (as it is known to be), the most conservative results are going to seriously shake the ground which we walk on.

[NecklyTyler]

2. The warming does not need to reach a level to 'melt' the ice to upset the equilibrium

We have already passed the point where the seasonable changes Arctic ice follow a predictable, repetitious pattern. The melting and refreezing of the ice each season will reach both greater minimums as well as maximums. The first year ice is thinner and more brittle than older ice giving it a propensity to fracture allowing the wind to blow the pieces about.

The wind moves vast quantities of ice from the Northern regions to warmer Southern regions where it melts. The following winter brand new, thin, brittle, ice freezes and the process repeats until a new equilibrium is reached. Under current climatic conditions, the Arctic ice pack will never return to what it was just a few decades ago.