James Hansen, head of NASA's Goddard Space Institute and a leading atmospheric researcher has just released a paper that says we are the edge of dangerous climate change (link). So far most climate projections have only looked at Greenhouse Gases and what will happen to the planet based on different GHG emmission scenarios (eg. what if have a utopian altenative energy future vs. full on fossil fuel consumption by the middle of the century).

But the Hansen paper looks at feedbacks. These are things like, when the arctic ice melts it exposes more water. Ice reflects, water absorbs. So the newly exposed water therefore absorbs more solar radiation and increases the warming which melts more sea ice and exposes more water and on and on it goes.

When considering this factor, they are saying that we are much closer to the "tipping point" than we may have previously suspected.

We cannot adapt to some climate change scenarios
I went to a talk yesterday by Prof. Stephen Schneider, a US climatologist from Stanford who was a lead author on one of the recent global climate reports from the IPCC (Intergvernmental Panel on Climate Change). He took us through the different scenarios from the lower version (1.1 – 2.9 degrees C warming), to the higher version (+6 degrees C warming). (note: even the lower version will have a doubling of carbon dioxide before levelling out in the 1.1– 2.9 range)

According to Prof Schneider, when they (IPCC scientists) are looking at how we can adapt to different warming scenarios, they don't bother to look at the +6 degree warming scenario...because he says "we cannot adapt to that scenario".

I also interviewed Dr Robert Correll, head of the Arctic Climate Impact Assessment a couple of months agao and he said that a planet that is 2 to 3 degrees warmer will be a very different world than the one we currently know. (Download latest WWF Arctic Bulletin)

I think what we don't realise on a day to day level is that these numbers aren't equatable to the typical warming that we feel when we are at the beach or walking down the street. It is not like the difference between a 20 degree day and a 26 degree day. A global average temperature rise of these amounts means the complete alteration (and destruction) of ecosystems and in many areas a severely diminished water and food supply (not to mention melting ice caps and sea level rise).