Heat is on the US as it claims that planting trees will stop global warming

Climate change: We've had the weird weather, we've heard the new warnings, now stand by for the real storm as the world tries once more to do something about it.

Climate change: We've had the weird weather, we've heard the new warnings, now stand by for the real storm as the world tries once more to do something about it.

Stubborn disagreements between nations are threatening in the next fortnight to derail the Kyoto Protocol, the 1997 treaty under which the world community agreed on a united front to tackle the danger of global warming.

On the one side is the United States - emitting 23 per cent of the industrial gases, such as carbon dioxide, known to be causing the greenhouse effect, but with just four per cent of the world's population.

And on the other is the European Union, and all those environmentally conscious states like Germany, Denmark, the Netherlands, and, it is fair to say in this case, Britain.

Between them looms a chasm - a visceral disagreement about how to meet the commitments they all entered into at Kyoto to make swingeing cuts in their emissions of carbon dioxide and other greenhouse gases.

It has been fudged over for two years, but at a big international conference taking place in The Hague, this week and next, it will have to be resolved, for better or worse, and there is no guarantee that it will be for the better.

Loopholes are the essence of the matter. The US, supported by Japan, Australia, Canada and some other industrialised countries, wants to achieve its Kyoto target in ways that Europe thinks will amount to cheating, if pushed too far.

They include buying notional emissions cuts from other nations - the so-called "hot air", sharing emissions reductions that come from energy-saving projects financed abroad, and most controversially, using forests to absorb carbon from the atmosphere, as "sinks".

A forest makes a great carbon sink. Trees and carbon dioxide go together: they take in the gas every day as part of the process of photosynthesis, the production of plant growth fired by sunlight, and naturally, a forest takes in a lot of it.

The United States thinks that planting forests is a good alternative to making actual carbon dioxide cuts in the American economy. Indeed, it thinks a good alternative is not cutting down forests which are actually there.

The European countries, genuinely trying hard to cut back their own emissions, see this as a brazen try-on; at the very least, they feel the idea is open to abuse. Can we measure exactly how much carbon a given forest of millions of trees is taking up? What happens to your commitment if the forest burns down?

The issue of sinks will loom large on the agenda, as part of the broader and tougher issue of just how far the US can meet its Kyoto target by using alternatives to real domestic emission cuts.

The Americans want no limit on the extent to which they can do so. They mean it. The Europeans insist that at least 50 per cent of the reductions in carbon dioxide emissions that any country makes must be from genuine energy cutbacks at home, such as having cars that use less petrol. They mean it too. Here comes High Noon in The Hague.

There is a growing international consensus about the reality of global warming and it might be thought this would knock heads together. There are still sceptics - for an entertaining example, see a whole page entitled "Forget Global Warming, It's Getting Cooler" by Nigel Calder, with the byline Distinguished Science Writer, in yesterday's Daily Mail.

But there is now no government of any country which does not accept man-made climate change as a real and immensely threatening phenomenon, and 160 of them are sending delegations to The Hague.

Recent research has made the threat even starker. The UN's official research body, the Intergovernmental Panel on Climate Change, is currently preparing its third assessment of the scientific evidence for publication next year.

Three weeks ago a draft of this paper was leaked. It shows that the hundreds of scientists involved now think the atmosphere will warm at twice the rate anticipated a decade ago, leading to global temperature rises, in the worst-case scenario, of 6C by the end of the current century. This implies absolute disaster for billions of people, with agricultural failure on a huge scale and a rise in sea level wiping out extensive parts of low-lying and populous countries, such as Bangladesh.

Britain's own climate scientists at the Met Office's Hadley Centre drew similar conclusions last week. Their computer models now predict, among much else, that the forests of the north-east Amazon will start to die back in the 2040s, and that summer sea-ice in the Arctic Ocean - essential for the survival of polar bears and walruses - will have almost disappeared by 2080.

But the sea-ice is already shrinking, and the polar bears and the walruses are already having problems. Glaciers are in retreat at a remarkable rate.

There has been a big increase in extreme weather-related natural disasters, such as Hurricane Mitch, which devastated Honduras.

While individually these phenomena cannot be ascribed with certainty to climate change, they are nevertheless consistent with predictions that more extreme weather events will increasingly accompany global warming.

And 1998 was the warmest year in the 1,000-year climate record created by scientists at the University of East Anglia using the data contained ice-cores and in tree-rings.

The US Government accepts all this. So why are the Americans not falling over themselves to cut back on their carbon dioxide emissions? The answer is simple: their Kyoto commitment, sanctioned by Al Gore at Kyoto, is impossibly large in practical terms.

The US has agreed to cut its emissions to a figure seven per cent below the 1990 level by 2010. Since 1990, however, the US economy has mushroomed in the longest boom in the country's history, and to slash emissions from where they will be a decade from now to seven per cent below 1990 will in practice, according to the chief US climate negotiator, Frank Loy, mean a cut of about 35 per cent.

That equates to something like seven billion tonnes of carbon dioxide, and short of laws which make all Americans get out of their cars and onto bicycles, it cannot be done by domestic measures alone.

The Americans have to have alternative ways of making carbon dioxide cuts if they are to meet their target; the issue at The Hague is how much they are allowed. If the US is seen to cheat, the Kyoto protocol will be worthless.

"Unless all countries play according to the rules and take action, all of us are going to suffer, as we have seen in the last three years, with floods, tornados and inextinguishable forest fires," the Environment Minister, Michael Meacher, said yesterday.

"The point is that the US accounts for a quarter of global greenhouse gas emissions and 36 per cent of emissions from the industrialised world," he said. "That is why it's so important that they concentrate on the domestic economy - that is the cause of climate change."