Arctic ice thaw may represent a 'tipping point'

There's that word again, may, it occurs an awful lot in anything where climate change is being discussed, so, at least for now, let's stick to the facts that we actually know.

We do know that this summer a record for the melting of the Arctic ice cap occurred; well, at least as far as accurate human modern records go back; "The Arctic summer sea ice shrank by more than 20 percent below the previous 2005 record low in mid-September to 4.13 million sq km (1.6 million sq miles), according to a 30-year satellite record."

We do know that the albedo effect can be scientifically measured; the white ice cover reflects an awful lot of solar energy back into space, whilst open sea water absorbs a lot more heat energy; therefore the less Arctic ice cover exists, the more heat energy is absorbed by the sea, thereby contributing to warming.

What we don't know is if there is any sort of 'tipping point', beyond which the ice will disappear far more rapidly, allowing far more heat into the Arctic Ocean and contributing significantly to global warming.

However, there is a lot of talk about theoretical tipping points, so when some 'experts' are suggesting that we are already past, at, or at least rapidly reaching the 'tipping point' for the Arctic Ice cap, then perhaps its time to start worrying. This, from PlanetArk, reports on the comments of the 'experts' involved.

"The reason so much (of the Arctic ice) went suddenly is that it is hitting a tipping point that we have been warning about for the past few years"

"In Germany, the Potsdam Institute for Climate Impact Research says Arctic sea ice has 'already tipped'."

"I'd say we are reaching a tipping point or are past it for the ice. This is a strong indication that there is an amplifying mechanism here"

Three different 'experts', three slightly different conclusions, but all enough, perhaps, to give us all some cause for concern.

The thing is, the disappearing Arctic ice will barely affect sea levels at all, but if the Greenland ice sheet follows in the steps of the Arctic ice cap at anything like the same pace, and there are some initial indications that this is happening, as we have already mentioned, then mankind is going to be facing some very serious problems over the coming decades.

"It is a very good lesson, because the ice sheets (on Greenland and Antarctica) have their own tipping points, somewhat harder to get started but far more dangerous for humanity around the globe"

The Greenland ice sheet holds enough fresh water to raise sea levels by about 7 metres if it all melts; that, I read somewhere recently, would do for over half of this planet's major cities.

Anyone fancy a trip to Arks'R'Us?

Addendum:
Cameron could have a bit of a tough time on the subject of climate change; it looks like the Tories' Freedom Association thinks that climate change is all a load of bull. See 'Tory climate change sceptics' from the Guardian.