SIR - Mr Thomson is a great advocate against global warming, and that the population is exacerbating the effect (T&A, January 11), and seems to follow this line of reasoning with a blind eye.

He states that you do not need a semi-Mediterranean climate to grow grapes, as they grow at present, even in Leeds.

Surely, that is my point, that the weather has changed enough for vineyards to move this far North, for they did not exist 30 years ago, nor could they exist now, if we were having weather patterns of that time.

I am not surprised at the weather change, for I have been expecting it for at least 30 years.

I am no climatologist, nor do I have a crystal ball, but I did listen to a farming programme which advised farmers that there was going to be a weather change, and that crop styles would have no move northwards, due to the south getting warmer, and so on, moving north.

So where does CO2 come in there, as it was intimated that this weather was a natural occurrence?

A G Goldsbrough, Dale Court, Fieldway, Ilkley