FOR A president of Britain's Royal Society, the world's oldest scientific academy, to openly and angrily attack a President of the United States is virtually unprecedented.

But Lord May's broadside against President Bush reflects the growing anguish at the Bush administration's obstructionism, from scientists who are concerned about the threat of climate change.

What America does - or does not do - has an enormous effect on attempts to come to grips with global warming, because the energy-profligate US, with 4 per cent of the world's population, produces a quarter of the world's carbon dioxide. It is far and away the biggest emitter of CO2 on earth.

So, in 2001, when Bush took America out of the Kyoto protocol, the treaty prescribing initial cuts in CO2 emissions for the industrialised countries, he did much more than give it a diplomatic body blow.

He invalidated the whole process, because as Lord May points out, the uncut, increased emissions from the US between the start and finish of the first Kyoto commitment period - 1990 to 2010 - will actually dwarf the cuts by other parties.

The subtext to Lord May's speech is in effect: we might just as well not have bothered.

Lord May's other concern is one widely shared on this side of the Atlantic: the increasing attempts, filtering down from the top of the administration, to deny the science of climate change. US climate scientists are increasingly cautious about speaking on the issue, fearful that their funding will be cut. The administration appears to have decreed, in an Orwellian manner, that global warming Is Not Happening.

This attitude has, weirdly, spread to Bush supporters among the public. Even journalists in Britain who report on the science of climate change receive e-mails from angry US citizens suggesting that - merely because one reports such things - one is an effete European cheese-eating surrender monkey.

Have a look at www.grida.no/climate/ipcc_tar/wg1/005.htm . It is chapter and verse - and it does not suggest that global warming is a myth.