Sir - What do a few "convenient untruths" matter, write your green warriors, if the cause is just?

The fact is that a cause which relies on untruths can never be just - but without them they have no cause.

Climate has always changed, but the green dogma that this time it's all our fault and we must be punished just doesn't stand up.

There have been natural cycles of temperature peaks and troughs since the world began, mostly when there were no exhaust emissions - or indeed humans - at all.

Britain's worst recent weather event is not this year's flooding, which was not due to particularly exceptional rainfall but to building on flood plains, but the pre 4X4 Great Storm of 1703.

Even the IPCC gives little comfort to the green fanatics. After years of public funding, with a clear brief to prove we're to blame, they still find it only "likely" that man is accelerating natural warming and even then only to a "discernible" degree. Their most doom laden forecast has temperatures rising by .02 degrees a year and sea levels by a foot a century - much the same as in the past. Hardly Gore's Apocalypse.

OK, say the green brigade, even if there is no evidence, what's the harm in doing what we tell you after all we might be right.

The harm is not just the obvious one - that all the sacrifices would leave us worse off as individuals, and hamstring our economy to no discernible benefit at all - but that if we are gulled, in pursuit of the green vision of a return to a pre-modern world, into believing we can switch off global warming by altering our behaviour it will stop us tackling the real problems that natural climate change may cause.

Michael Tyce, Waterstock