Source: BBC Radio 4: Today Programme
Date: 01/11/2014
Event: Nic Lewis: "The models are all over the place..."
Credit: BBC Radio 4: Today Programme, also many thanks to Fay Kelly Tuncay for saving the audio segment
People:
Sarah Montague: This weekend, the UN's climate panel will produce its five-yearly Bible on climate change - it's called the IPCC Synthesis Report. It'll warn that the rate at which greenhouse gases are increasing will mean irreversible changes to the planet. The IPCC is the world's biggest peer-reviewed scientific process, but its reports are always resisted by a very vocal minority. This time round, the critics and the mainstream appear to be moving closer together on the science. So are the "climate wars" over? Our Environment Analyst Roger Harrabin reports.
Roger Harrabin: I've been seeking the views of some of the UK's most prominent climate change sceptics, and there is now among them a fairly broad agreement on some of the basics of climate change. Firstly, CO2 from humans has almost certainly contributed to warming the planet. Secondly, the current pause in warming is likely to end some time, because of increasing CO2. And thirdly, if we double CO2 emissions - which we're likely to do, later this century - we're likely to provoke a temperature rise of about 1.7 degrees. If you take into account the uncertainties, it'll be between 1.25 and 3 degrees.
Now that's significant, because the UN's identified 2 degrees as a danger point which we shouldn't cross. Now, these projections put the sceptics' forecast almost completely within the range outlined by the UN climate panel. So, is the climate war over? Well, far from it, but both sides have moved closer towards each other. The sceptics still think the IPCC's computer models exaggerate future warming, though, and their concerns are articulated by Nic Lewis, an independent scientist based in Bath.
Nic Lewis: The models are all over the place - this is not just basic physics that they are representing - and as a result, their projected warming, for a doubling of CO2, is uncertain and is much higher on average than my best estimates from observations.
Roger Harrabin: Mainstream scientists defend their models, but Mr. Lewis, who is a Cambridge-educated mathematician with a career in financial consultancy, has become something of a figurehead for sceptics. The sceptics I've spoken to, including the influential blogger Andrew Montford, think he's on the right track. Unlike most sceptics, he's published his work in scientific journals and although most mainstream scientists think his calculations are too low, they are taking his critiques seriously. If he's right - that's if he's right - and we get 1.7 degrees of warming for doubling CO2, that would give governments more time to cut emissions, which would be very good news, given our struggle to reduce CO2 emissions. But listen to this. [To Nic Lewis.] Are you at all worried about what we're doing with the climate?
Nic Lewis: I think it's logical to be worried, because we don't know what the exact effects are, and we don't know how much we need to do to counteract them.
Roger Harrabin: Mr Lewis says he doesn't lose sleep on these issues - there are plenty of things for politicians to worry about, he says. But, for all that, we have reached the point now where many climate sceptics are singing off the same hymnbook as mainstream science over the effects of CO2, even if they are by no means on the same page, and even if they interpret the risks very differently. So it's now up to politicians to decide how to respond to the risks and uncertainties of increasing CO2, and that'll be the focus of talks, over the coming year.