Leading article: A climate change warning we ignore at our peril

Alarming new temperature forecasts show the need for urgent action

Two years ago, the United Nation's International Panel on Climate Change forecast an increase in global temperatures by the end of the century of between 1.8C and 4C, depending on the success of nations in reducing their carbon emissions. But now an international team of scientists, led by Professor Corinne Le Quéré of the University of East Anglia, argues that the world is in fact on course for a 6C rise in temperature by 2100. These might sound like small numbers. But their implications could not be bigger – or more dangerous.

We have long known that, unchecked, climate change is likely to result in a serious reduction in global agriculture, chronic drought, rising sea levels and the mass displacement of populations. But the implications of a 6C rise are more disastrous still. They include the acidification of the oceans, the loss of all polar ice and the combustion of the rainforests. It is doubtful that mankind could survive such a catastrophe.

The instinct of many will be to dismiss such forecasts as scaremongering. That would be a serious mistake. These forecasts are based on authoritative research. They are not the predications of religious fanatics or superstitious hysterics, but men and women of impeccable scientific credentials. And unless we get our carbon emissions under control over the next decade there is a real chance that we will be heading for the sort of world they describe.

According to this latest study, between 1990 and 2000 the average annual increase in carbon emissions was 1 per cent. But between 2000 and 2008 they increased by 3 per cent on average a year. Far from coming down, our emissions are accelerating. And the explanation can be reduced to one word: China. The world has been on an unsustainable high emissions path for many decades. But the breakneck industrialisation of the Middle Kingdom over the past decade has put us on a short road to irreversible disaster.

We also report today of renewed hope that there might yet be a deal between the Obama administration and Beijing over emissions cuts – probably not in time to produce a binding global agreement for the UN Copenhagen summit next month, but possibly sufficient to enable a successor to the Kyoto Protocol to be signed next year. What this latest scientific temperature projection emphasises is that such a deal is not a political luxury, but a moral necessity.

Since the recession broke, resistance has been growing among some politicians around the world to the measures which will be needed to reduce emissions – taxing carbon-emissions, mandating greater energy efficiency, investing heavily in low-carbon energy sources, paying money for developing nations to conserve their rainforests – on the grounds that the costs will have to be borne by the public.

The scenarios associated with a 6C temperature rise ought to expose is just how wrongheaded and short-sighted such an attitude is. Any upfront costs that will be required to clean up our economies cannot rationally be compared to the costs that runaway climate change threatens to inflict on the entire planet.

But delay is just as dangerous as myopia. The longer our leaders leave it to begin the work of cutting carbon emissions, the more the opportunity to limit the rising temperature of the earth shrinks. The warnings are clear. The time for action is now.