Some Lib Dems have doubts over Sir Menzies' position

Carbon debate

Environment spokesman Chris Huhne said tackling global warming would need an "enormous economic change".

He set out plans to make Britain carbon neutral by 2050 at the party's annual conference in Brighton.

The Lib Dems are trying to regain the initiative after high profile Tory and Labour green announcements.

Look you need a thick skin in this business... and the one thing the public does see through is if you try to be something you are not

Sir Menzies Campbell

At-a-glance: Day one Send us your comments

Mr Huhne warned that climate change means "far more wild weather" following the devastating floods over the summer.

Setting out his "green vision", Mr Huhne warned there was little time left to change the way people live.

Some of the other key proposals in the Liberal Democrats' Zero Carbon Britain plan are:

Introduce green mortgages to encourage more environmentally friendly homes

Charging lorries to use the UK's roads in order to double rail investment, possibly creating a high speed line running north to south

Boosting spending on flood defences to respond to climate change

Encouraging microgeneration by paying a higher rate to producers who export energy to the National Grid

Creating a climate change levy of £10 on domestic flights

The conference voted to reject a call by MEP Chris Davies to end the party's opposition to nuclear power.

Before his conference speech, Mr Huhne told reporters: "With these plans we can restructure the economy towards a basis that is based on renewable energy not on fossil fuels.

"It's an enormous economic change but it's an economic change in line with changes which we've seen in the past, for example between the end of the 19th Century and beginning of the 20th Century moving from steam power to the petrol engine, moving from gas light to electric light."

Mr Huhne's proposals received the overwhelming backing of the party conference.

Nuclear motion

Lib Dem leader Sir Menzies Campbell said his party was the only one to stand up and say what has to be done to address climate change.

"We should be working towards a carbon-neutral Britain by 2050. We should be working towards the elimination of petrol-driven motor cars," he told BBC1's Breakfast programme.

"We should be really radical in what we do - the urgency of the problem is really enormous."

The conference motion says the scientific evidence for climate change is "overwhelming" and that "if decisive action is not taken in the next decade, any prospect of a stable climate may be lost".

This is being challenged by Chris Davies, the party's climate change spokesman in the European Parliament.

Unfair

He said: "I have always been opposed to nuclear power. It is expensive, creates a legacy of radioactive waste and has absorbed public resources that should have been used to develop alternative technologies.

"But the imperative now is to fight global warming. We cannot ignore the fact that our existing nuclear power stations do not release carbon dioxide.

"Carbon emissions will rise as they come to the end of their lives."

Meanwhile, Lib Dem Treasury spokesman Vincent Cable attacked the government over the Northern Rock crisis.

He unveiled research suggesting voters believe the wealth gap in the UK is unfair.

Hear more on the Lib Dem's views on airport runways and petrol taxation in a Newsnight interview with Sir Menzies Campbell - Monday 17 September, 2230 BST, BBC Two.