Mr Bush's insouciance over global warming will soon seem out of date

With the optimism of its youth, The Independent prefers to hope where others despair. The crisis of the Kyoto agreement on measures to deal with global warming, however, cannot but prompt gloom about the future. There are several potential reasons for looking on the bright side of life which, upon examination, turn to dust.

It could be argued, for instance, that the Kyoto Protocol was so inadequate in relation to the scale of the threat posed by human-made climate change, that it makes no real difference whether or not it is ratified. Not so. The targets agreed at Kyoto in 1997 would have, it is true, only a limited effect in restraining the growth of the world's carbon dioxide emissions ­ requiring rich nations to cut emissions back to below 1990 levels, while giving poorer countries scope to burn more fossil fuels.

The signing of the protocol was, however, a hugely significant event, in that it secured the assent of all the nations of the world to the principle of legally-binding limits on emissions ­ having accepted at the Rio conference five years earlier that global warming was happening and that steps ought to be taken to mitigate it.

What is more, the basic structure of the Kyoto deal was right, which was that the rich, energy-hungry countries should lead the way by cutting their emissions, before demanding that developing nations make a similar sacrifice. All that has now been rejected by the one nation whose participation is most essential, the United States.

The other reason for thinking that there might be a silver lining to the pall hanging over the world's greatest polluter, is that President Bush's rejection of Kyoto simply makes explicit the fact that the US was never going to ratify the treaty in any case. There is some truth to that: the US Senate, which has the power to ratify treaties, is deeply sceptical about the science of global warming and is overwhelmingly opposed to the protocol.

There is some benefit in President Bush's directness, therefore, in highlighting the difficulty of persuading the American people of the need to use less energy. Simply demonising George Bush as an individual ­ misguided though he is ­ serves little purpose. Those who want to see the governments of the world move towards sustainable economics, must sell their case to peoples all over the world who enjoy or want to enjoy the American way of life.

There is no doubt, however, that the chances of persuading either the Senate or the wider American public of the need for change are much lower under George Bush than they would have been under Al Gore ­ paradoxically denied the Presidency by the self-defeating "green" candidacy of Ralph Nader.

The realistic optimist, therefore, accepts that a major battle in the war against global warming has been lost, and prepares for the next push. International agreements are often messy and imperfect, processes rather than events. The treaties which liberalised world trade after the war started with the General Agreement on Tariffs and Trade in 1947, but the World Trade Organisation which was envisaged then was only set up in 1995.

The European Union, Russia and Japan ought to proceed with ratifying the Kyoto Protocol, in preparation for an eventual change of mind in the US. That may take some time coming, but the alternative is a counsel of despair: to give up on the whole project and lapse into the easy posture of blame and protest.

The science of global warming is sound; and even in the US, anti-science such as creationism cannot hold out for long. Mr Bush's insouciance about global warming in Europe this week will soon seem out of date, even through American eyes.