Mark Walport's call for a grown up debate on climate change has prompted a couple of responses in the letters pages.
Sir, Sir Mark Walport (“Top scientist tells climate sceptics to grow up”, Jan 27) is right that we need a grown-up debate about what to do about climate change. However, that can only take place if some light is shone on the scientific uncertainties around the matter. Most scientists agree that man is affecting the global climate, but this agreement is insufficient to inform policy as there is no consensus about the degree of man’s contribution to rising temperatures compared with other natural factors beyond our control. Given the expense of many of the proposed climate mitigations, it is right that these uncertainties are discussed openly as part of Sir Mark’s grown-up debate. It may well be that we are best to do nothing for the moment.
Robert Birch
Brompton, N Yorks
Sir, I should remind Sir Mark Walport that there are more Fellows in the Royal Society who are sceptical of the ways of the IPCC than Fellows who work within the fields covered by that organisation. If the climate change case comes to be seen as having been oversold, and billions of pounds misinvested, the credibility of science advice will take a terrible blow.
Professor Michael J. Kelly, FRS
University of Cambridge