Source: BBC Radio 4: Today Programme
URL: N/A
Date: 26/01/2012
Event: David Shukman on Defra's UK Climate Change Risk Assessment
People:
James Naughtie: What do the likely changes to the climate mean for this country, for the rest of the century? For the first time, the Department for the Environment, Food and Rural Affairs has tried to make an assessment, in a 2,000-page document, that tries to make a best guess about the challenges for government and for individuals. Water supplies, rising sea levels, changes in the patterns of health, and so on... But it's quite frank about the huge uncertainties that surround any predictions. David Shukman is our science editor. And, David, it is - it's vast, it deals with all kinds of issues, but it is quite cautious, in a way, isn't it.
David Shukman: Well, yes, I mean, the remarkable thing is, despite this vast body of work - the 2,000 pages, three years' studying in detail 11 different sectors of the economy - there aren't very many surprises. So, for example, hotter summers, they say, will lead to perhaps another 6,000 deaths beyond the average per year, by the middle of the century, but that's more than outweighed by 24,000 - up to 24,000 - fewer premature deaths, because of milder winters. So there's a - if you like, a sense of trade-offs here. Clearly they identify some pretty big negatives, in particular damage from flooding, although the range of scenarios for what that could cost is pretty large. They're worried about water shortages in various parts of England, especially the Thames Valley. But they're quite keen to highlight some opportunities for business. For example, agriculture - wheat yields, they say, will go up by 40 to 140%, because of a longer growing season.
James Naughtie: What assumptions are they making about the very thorny question of - well, let's just use the shorthand phrase "global warming"?
David Shukman: Well, that's a fascinating question, and they try to tackle it by saying we have to look at a range of scenarios. It all relies on modelling, and of course that brings an inherent set of weaknesses, because you have to make assumptions. So they have different scenarios for how much and how fast greenhouse gas emissions will go up in the coming years, and then on top of that, another range of assumptions about what effects those rises might have. Now they acknowledge the huge range of uncertainties here. I mean, they highlight, for example, the effect - possible effect - of sea-level rise on London. I mean, they say, at the very least, the sea could rise by 30 centimetres, about a foot, or go up by 190 centimetres by the latter part of the century, nearly 6 foot. Now that - they themselves bring that out to show, actually, with this enormous possible range of outcomes, it's actually quite difficult to plan.
James Naughtie: Yep. David Shukman, our science editor, thanks.