The nub of Christine Wheeler's letter on climate change (Beware doom scenario, Letters, July 5) seems to be to dispute there is climate change, even less our effect on it. In effect: 'do nothing, don't worry'.

Flitting from solar cycles to levels of greenhouse gases in the atmosphere, her thrust is 'it doesn't matter: we've all been here before'.

But that's the problem: WE haven't!

Yes, the earth may have had had higher carbon dioxide levels in the Cambrian period - some 500 million years ago: long before man appeared.

In fact, the present amount of CO2, which has risen nearly 50 per cent since the industrial revolution (to 400 parts per million), is the highest it has been in 14 million years.

Christine cites solar cycles. Solar cycles, an observed 11 year fluctuation in the sun's activity, are irrelevant to the long term changes.

Irrespective of these cycles, the underlying trend shows the world is getting warmer. And not only that but the overwhelming consensus of the world's most eminent scientists is that there is a 95 per cent link between the warming and our activity.

Which is hardly surprising really considering the burning of millions of gallons of oil daily under the collective bonnets of millions of cars; not to mention lorries, ships, planes, trains - has to have some heating effect - that of several volcanoes erupting relentlessly around the clock.

Yes, we are in uncharted territory: of course there are still lots of pieces missing in the jigsaw to be able to see the complete picture. But the evidence so far is damning. Yet Christine's argument seems to be, 'as we don't know, no there isn't a problem: carry on like it's business as usual'.

Dave Degen

Whippendell Road, Watford