CHRISTIAN VASSIE (Letters, January 1) berates me for saying coal is “virtually unlimited” by saying: “No it’s not, it’s a finite source by definition”.

Well, Mr Vassie, the word “virtually” means “nearly” or “almost” so by your saying coal is a finite source you are agreeing with me.

All our resources are finite and there will eventually come a day when all oil, gas and coal are exhausted.

Humanity will be particularly hard hit when oil is exhausted as it provides so much for the smooth running of our daily lives.

The Greens are constantly attempting the stoppage of oil and gas exploration with their expeditions, seemingly unaware of the irony of using diesel-powered ships to harass exploration vessels.

The recent failure of the large contingent of climate scientists to show how man-made global warming was wreaking havoc with the Antarctic ice-shelf came horribly unstuck when there ship was trapped by ice.

The ice which trapped them should, according to them, have been a long way away as it should have melted.

Philip Roe, Roman Avenue South, Stamford Bridge, York.