Friday, February 16, 2007

Next 30-40 years climate is already locked in

Dr Chris West is Director of the UK Climate Impacts Program. The government funded them to co-ordinate predictions on the impacts of climate change in Britain.

Chris West: The climate we will get over the next thirty or forty years has almost all been determined already by emissions that we've created in the past. So for the next 30 or 40 years we've got one climate future to look at, and then the climate futures start to diverge depending really on what we choose to do now, whether we choose to go on emitting more and more greenhouse gases, or whether we start controlling greenhouse gases. I think people have built up this expectation that science will give you an absolute answer. People take decisions based on very patchy, feeble, messy information all the time and yet they expect climate information to be exact, and I think that's a nonsense. We use four separate scenarios of future climate in the UK for this current century. People come to us and they say what's the most likely? And we can't tell them that, they say well, what's the worst case? We can't tell them that either. All we can do is say look, here's a range of possible futures, it's up to you to plan for these futures. The earth hasn't experienced the temperatures we're going to get in the next century for possibly a million years, so there's the danger that we stray from conditions that we know something about into conditions we've never experienced before.

One of the nasty surprises we could be facing is both the Greenland ice sheet and the West Antarctic ice sheet have the potential to melt faster than we anticipate, and either of those could add six or seven metres to sea level. So if we face that sort of sea level rise, then there are very, very serious political, economic and social impacts for the whole world.

Naomi Fowler: Let's say the climatologists are right and the world's already committed to a metre rise in sea levels. We Brits can only expect the erosion of our coastline to accelerate, if as predicted, this century sees wind speeds 6 to 7 per cent stronger. That means a 15 per cent increase in wave height and that causes a level of storm damage that's a whopping 60 per cent higher than it is now. Add to all that the phenomenal rainfall we're getting and we get a very alarming increase in coastal and river flooding.

My comments

To put that into perspective:
Any sea rise in vertical metres should be multiplied by about a hundred to get the approximate amount of horizontal meters in coastal erosion. That means that a mere one centimetre vertical rise results in about a whole metre horizontal erosion. This I compiled from previous informations.

And it seems to be supported well if you look at the roll on effect of how a 6-7% rise in wind speed can relate to a possible 60% higher storm erosion or damage.

Science Show - 3�February�2007� - Rising sea level in Britain

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