From Mr Markus Shaw.

Sir, Vaclav Klaus, in his article "What is at risk is not the climate but freedom" (June 14), displays the instinctual reflex of the sceptic and libertarian: both are traits that I can admire. But we should remember that, until very recently, the scientific community as a whole was sceptical about climate change and the man-made causes of global warming: this began to change only when the weight of evidence began to stack up in favour of scientists advocating these theories, who until then were the lone voices. We should also accept that scientific consensus is usually reached through weight of empirical evidence, not mass delusion.