SIR – In his letter (T&A, January 30) Keith Thomson had obviously misread my, what he called, courageous letter in respect of over-population.

I had not said that it contributed to climate change, but that it was even more important than it.

Whereas I am not at all convinced and become even less so daily, in light of further news of the IPPC’s ‘scientific’ sources, I am certain that man is responsible for burdening the planet with a population that is becoming more and more unsustainable.

Philip Bird, Nab Wood Terrace, Shipley