I DON’T know which planet John Peek is on (‘Climate story speculative’, Letters, May 6) but the one which gives most concern (Earth) is warming at a dramatic and unprecedented rate.

Polar and glacial ice is in alarming retreat and weather conditions in various parts of the globe are becoming ever more extreme.

Historical examples of naturally-occurring climate change have, by definition, no bearing on man-made global warming caused by increasing CO2 emissions dating from the industrial revolution.

The effects of these emissions are cumulative and, unless we take drastic action to halt the trend, may become irreversible.

The various computer models used by climate scientists are constantly being refined in the light of further evidence and informed criticism. This is the very stuff of science: the models are not thus 'discredited' but improved.

A ‘speculative’ element is inevitably involved in trying to calculate the effects of varying levels of emissions into the future and much of this depends on what action we take.

We cannot say the evidence is inconclusive: it is as solid as the evidence of a link between smoking and lung cancer.

This, too, took some time to be universally accepted, as vested interests, to their shame, spread misinformation and enough doubt to delay action. Here is the real 'politicisation'.

IAN STANNAGE, The Grove, Bournemouth