WHAT a shame that Dave Hampton gets off on the wrong foot by claiming that "there are very few free thinking people left who deny the reality of fossil-fuelled climate chaos!" This telescoping of all the blame for any observed changes in the world's climate on carbon dioxide emissions is the cause of all the trouble, and I believe that this is what Mr Weedon objects to, as I also do.

No right-thinking, technically educated person would exclude atmospheric carbon dioxide as one of the factors contributing to the Earth's greenhouse effect. The evil in this whole argument is the gross exaggeration of this contribution - fostered by misguided and even malign official publicity - which unfortunately pervades general public opinion to the exclusion of reasoned and detailed argument. As a self-proclaimed MA (Cantab) and C Eng, Mr Hampton should know better than to dismiss the contributions of Mr Weedon and others to this dialogue, especially in view of the concern he expressed for fuel conservation and the efficient use of energy!

One of the characteristics I have noticed in such debate is the mixing-up of aims: "saving the planet" by trying to reduce fossil-fuelled carbon dioxide emissions (ie countering climate change, as if Canute's historic example were not enough!), and conserving energy. It may be that other messages to conserve fuel would not have the necessary imperative, but the danger is that mixed messages end up in disaster!

Having just studied the key technical text of the IPCCs 4th Report, I am bound to say that their science appears to be flawed, giving the impression that the authors are happy - no doubt for political reasons and financial gain - to pile misery on misery at the feet of anthropogenic carbon dioxide, completely ignoring fundamental thermodynamic factors which severely limit the solar gain factor which the greenhouse effect contributes, nearly all of it powered by the atmosphere's water vapour and cloud content. They omit to say that all greenhouse gases compete with each other for the capture of the Earth's infra-red radiation, each one partly reducing the effect of the others; and that this effect has a definitive, absolute ceiling which has already almost been reached by the atmosphere's ubiquitous water content!

R Taylor BSc (Eng Hons), Dip Chem Eng, C Eng, MIChemE, FCIWM, MCIWEM Abbotsbrook Bourne End