IS MY memory playing up? As I recall, it was only last month that the United States car industry was in top gear, trying to stop agreement on fighting global warming in Kyoto. And wasn't it forecasting ruin if the treaty was adopted, saying that it would not be able to meet the target set for reducing pollution?

I ask because several of the largest US auto manufacturers are unveiling well-advanced plans for new, much cleaner cars, designed to capitalise on the very targets they opposed so vehemently. And the biggest of all has even started calling for further action against pollution to hasten the demise of the gas-guzzler!

After a screeching U-turn, General Motors, Ford and Chrysler are racing to bring out the low-pollutant car long written off as impractical and over-expensive. William C Ford Junior of Ford - one of the most aggressive firms in the run up to Kyoto - now says that the first to market it will gain a big competitive advantage. "There is a compelling business case to be made," he says, somehow managing not to blush.

Ford is to announce plans tomorrow, Chrysler on Tuesday. But General Motors - which makes one in six of all the world's cars - has beaten them to it. Last week it unveiled several prototypes that will do 60 to 80 miles to the gallon (thus emitting much less carbon dioxide, the main cause of global warming), promising to have the first in mass production in three years. Harry Pearce, its vice-chairman, has called for taxes on petrol to go up - about as close as you can get to high treason in the US without ending up on Death Row - so as to sweeten the market for them.

So, what is good for General Motors really is good for the planet.

RATHER more than a quarter of a century ago, when I was starting out on covering the environment, I met the man responsible for cleaning up Tokyo's once almost unbreathable air.

He told me how, whenever he proposed a new anti-pollution measure, the car-makers would say that it was impossible for them to comply. "We always say we will go ahead anyway," he told me. "Suddenly, a new invention comes up!" The new Damascene conversion of the US car manufacturers is partly due to their Japanese counterparts. They refused to join the campaign against the treaty and unveiled several very low-polluting, fuel- efficient models at last year's Tokyo Motor Show, while the US was proudly presenting the usual gas-guzzlers.

Toyota is already selling a 70mpg car in Japan, and if you turn on the TV in the US (something I try not to do very often) you can catch a Honda advert promoting a low-pollution car. The Americans suddenly realised they were about to lose business, which, admits John Smith, General Motors chairman, "crystallised" the mind.

But let's cheer, rather then sneer - though perhaps a jeer or two is okay - for this just might be the moment when the global-warming battle starts to be won. Industrialists, like most of us, prefer to go on in the same old way. But once it is clear that the rules have changed and that the new money is to be made in reducing pollution, they can move astonishingly quickly (wrong-footing tame legislators, who traditionally echo the corporate cries of horror but who are now lumbering along to try to keep up). Thus the CFCs that damage the ozone layer have been phased out far faster in rich countries then was stipulated by law.

Patient readers may remember that I was banging on before Kyoto about the need for concrete targets to set this process off. But I never expected the first signs of it to appear so soon.

TALKING of appearances, I made an unscripted one when I went to the off-Broadway show Tubes by the Blue Man Group last Wednesday.

Before the show - an exuberant display of performance art - greetings to a few members of the audience are flashed up electronically. I found myself hailed as "an average guy of no particular distinction, which makes it all the more important for him to know we love him", and ended up standing, waving regally while the whole theatre shouted: "We love Geoffrey Lean!"

Now I know what it feels like to be a member of the Royal Family. Or, come to think of it, perhaps not.