Leader: Gummer - a green voice in a grey wilderness

Something strange is going on. A Cabinet minister has been running around for three years saying the sky is falling, and nobody pays a blind bit of notice. He was at it again this week. "The sea is rising. The world is heating up. Governments of the world have to do something." It was John Gummer, explaining that humankind has changed and is changing the world's climate. Oh, him, you might say. Indeed, the very same politician who called on Wednesday for planning committees to let rich people build "exceptional" new stately homes in open countryside. But do not let that put you off. On climate change, he is right and should be taken seriously.

In 20 years' time, the British climate is almost certain to be slightly but significantly warmer than now. Mr Gummer warned that different crops will be grown and several animal species will be driven northwards into Scotland or extinction. It is remarkable to hear a government minister speaking in such definite and apocalyptic terms, and perhaps it is partly because he sounds so unlike our expectations of a politician that we do not pay enough attention to what he says.

He has been saying it for some time. At a conference in Geneva six months ago, he compared the lack of international action on global warming to the failure of the League of Nations to prevent the Second World War. We are so impressed by his green passion that we can forgive him this hyperbole. Climate change is real. We have already burnt so much fuel that the world's weather will be different in the next century from what it would have been without human intervention. We do not yet know what many of the differences will be. And we do not know how big or damaging the changes will be. Poorer countries could be badly affected, while some countries, including the United States and Russia, could benefit agriculturally from a small amount of warming. But the risks are high and there is a strong argument for messing about with the world's climate as little as possible. This means taking quite dramatic action quickly.

The trouble is that the vast majority of us are in two minds, which operate on different timescales. Sure, we care about the future of the planet, maybe not for ourselves but certainly for our children. And yes, we want to use less petrol, electricity and gas. In our other mind, though, we love our cars and we need our white goods and electric gizmos. This a dichotomy that is not well recognised by green pressure groups, which fantasise about people being priced out of their cars and onto cleaner public transport. But we love our cars, and with very good reason. Petrol taxes may be going up and up, but it does not matter - we are still going to drive door-to-door in private, comfortable, music-filled bubbles.

And it is this short-term mind that votes. Even when climate change does present itself as a short-term problem, as it did yesterday with the announcement by the water companies of a continuing drought in south-east England, the political effects are confusing. Because of the hostility generated by water privatisation, global warming is seen as just another excuse on the part of fat cats who do not want to pay to repair their leaky pipes. The charge is unfair, but one is tempted to ask - if Mediterranean countries can supply their population with water, why can't we?

In a sense, it is remarkable that the Government has achieved so much, acting on a 20-year problem in a five-yearly political system. Mr Gummer has been lucky, in that the drive to reduce the emission of greenhouse gases has coincided with Britain's power stations switching from coal to gas, which means we will quite accidentally meet the target for 2000 which was set at Rio de Janeiro in 1992. But he must also take the credit for pursuing many of the right policies. Putting up petrol tax by 5 per cent more than inflation every year may not force us into trains and buses, but eventually it will encourage us to buy cars with smaller engines. "Green taxes" on electricity generation and air transport are more difficult, but even here Mr Gummer has said some of the right things. Jet fuel is presently untaxed, partly because it would need international agreement, and he has asked the international civil aviation body to look at it - "we do not mean look at it and say nothing can be done", he said.

The Labour Party looks as if it would follow the same general course in government - if only because green levies could be the answer to Gordon Brown's Need To Raise Taxes that dare not speak its name. Almost unnoticed earlier this month, Labour passed up the chance to embarrass the Government in the Commons. Dawn Primarolo, Mr Brown's junior responsible for environmental taxes, did not oppose the doubling of the Tory airport tax in the Finance Bill. This was one issue where the Ulster Unionists could have been tempted to vote with Labour, because Northern Ireland is dependent on air links. But the airport tax is a sound environmental measure: Ms Primarolo, once dubbed Red Dawn as Tony Benn's adjutant, has passed through a Pink phase to become Green Dawn.

The environmentalists constantly bemoan Mr Gummer's isolation in a predominantly "grey" rather than green Government, along with Tony Blair's apparent lack of interest in environmental issues, and Michael Meacher's low status as the opposition's green spokesman. But it is unrealistic to expect much more of either main party, especially in the run-up to an election fought on short-term issues.

The right response to global warming is to tax energy as much as possible and to take a leading role in persuading other countries to impose green taxes too, rather than seeking to undercut each other. Mr Gummer deserves our praise for doing more than could be expected. We'll just have to forgive him the nonsense about stately homes.