We are guilty of a heinous crime against nature

THE Intergovernmental Panel on Climate Change forecast of global warming up to 2100 is not just a projection, as Dr Colmán Etchingham claims (Letters, March 25) — it is a prediction based on a sophisticated computer model of the earth’s climate which has been validated by ‘backcasting’ — in other words, testing with historical data to see if it correctly predicts the present.

The fact that there has been climate change in the past and that it was affected by things other than human activity does not disprove the IPCC’s climate change theory.

These factors are well understood and are incorporated into the model. No one who understands anything about weather and climate would construe the reluctance of meteorologists to attribute any specific extreme weather event to global warming as expressing doubt concerning climate change theory.