By Alex Kirby
BBC News Online environment correspondent
The leader of the British Conservative Party, Michael Howard, has spelt out his environmental policy priorities.
Old nuclear plants are closing: Some say the UK needs new ones
He told an audience in London he cared "passionately" about the environment, and proposed some significant changes.
But he had little to offer on cutting aircraft pollution, a rapidly growing concern, and he did not mention nuclear power, either to praise or to damn it.
It was a speech which left some hearers urging Mr Howard to be more ambitious, and not to fear pressure from industry.
Blazing the trail
Mr Howard, environment secretary in a Conservative government 12 years ago, is the first party leader to have held the post.
He said one of the main green achievements of the present Labour government - reducing greenhouse gas emissions - was built on Conservative foundations.
Saying the UK had "a privileged relationship" with the Americans, he accused the prime minister, Tony Blair, of "squandering this opportunity, because of our failure to follow up bold rhetoric with action that inspires trust."
"It is very disappointing", Mr Howard said, "that Tony Blair has not succeeded in persuading the present [US] administration that the challenge of global warming is one that cannot be shirked."
There were some smart policy moves: Mr Howard committed a future Conservative government to phasing out hydrofluorocarbons (HFCs), an ozone-friendly replacement for chlorofluorocarbons (CFCs) which are themselves potent greenhouse gases.
He suggested using the tax system to encourage homeowners to become more energy efficient by reducing stamp duty, a tax on the buying and selling of property.
Leaving them guessing
He praised micro-generation, low or zero carbon power generated by households, small businesses or communities to meet local needs, and combined heat and power schemes.
But there were some omissions in what Mr Howard himself said was "the case for new leadership in the way we manage our environment."
"Transport contributes around a quarter of our emissions and that proportion is expected to grow, not least as aviation emissions are expected to double by 2020," Mr Howard said.
The Conservatives would not duck, "as this government has done, the challenge of getting under control the fastest growing source of greenhouse gases - aviation."
Aviation needs some hard choices
So what would it do? "We should do more to inform consumers of the environmental impact of their choices. We should work to reach faster conclusions on the feasibility of including aviation in a European Union, and eventually global, emissions trading scheme."
Well, yes. But it is hardly the stuff to open up "clear blue water" between Conservative and Labour. And Mr Howard observed a total silence in his speech on nuclear power.
Asked by BBC News Online whether he thought the present government should plan a new generation of nuclear power stations, he said only a government was in a position to say.
Mr Howard said the basis for deciding had to be an assessment of possible alternative energy sources and how secure they were.
"Only a government can take that decision", he said. "We'll decide when we return to government."
It was a speech which drew praise from many. But Friends of the Earth urged Mr Howard to "stand up to powerful lobbying from industry and the motoring lobby".
The Green Alliance, co-hosts with the environmental consultancy ERM of the event, felt there was still room for him to be bolder. It was certainly a green speech, but a little too pastel for some of the audience.