Brian Beck as an intelligent layman (Letters, May 14) raises some points about global warming which requires an answer.

I, as a one-time lecturer at Brighton Polytechnic (now the University of Brighton), have to say he has only been given some of the facts on a subject which is not as simple as it appears.

Global warming was predicted 200 years ago by the Swedish chemist Svante Arrenuis, who’s predictions have come true.

The temperature rises are at present very small because a second phenomena occurs: global ice melting.

The rise in air temperature is mopped up by the melting of ice, each kilogram of which absorbs 30 kilo-calories of the latent heat of ice.

The ice cover over Greenland and Antarctica is enormous. This is acting like a deposit account in a “bank of cold”. The problem is not for us, but for our heirs many generations away. As responsible people, we have to consider what can be done.

It is also a fact the tree line in Canada is slowly advancing north, as is the wheat belt.

The loss of ice in Western Greenland has uncovered rock that has been encased in ice for several ice ages. This rock is shrinking, mined by a number of mining companies.

These facts will not go away. I do not pretend there is a simple answer – we have to do our best as individuals.

Roger Dalling, Avis Close, Denton