Climate-change sceptics no help
I think Dr Alan Rogers ('Climate claims need evidence', Letters, March 8) is missing the point. There may be arguments or evidence disproving man-made climate change, but 'deniers' misuse facts, propose non-sequiturs and postulate conspiracy theories.
He seems to argue that because carbon dioxide comprises a mere one part in five million of the atmosphere it cannot have any effect, but the rest of the atmosphere -- nitrogen and oxygen -- does not cause a greenhouse effect and there is no doubt that the 50pc increase in CO2 comes from burning fossil fuels.
He is right that CO2 levels were higher in the past (up to 10 times higher) but temperatures were much higher too (10 degrees) and the changes took place over millions of years, not over a century.