Election 2015: Parties battle over climate change action
Politicians from five political parties have clashed over action to tackle climate change - with UKIP arguing it is not caused by humans.
Conservative energy minister Matt Hancock praised the government's record on reducing carbon emissions.
But Ed Davey claimed the Lib Dems had to "fight every day" with its coalition partners for renewable forms of energy.
Shadow energy secretary Caroline Flint refused to rule out fuel duty rising under a Labour government.
The Green Party's Andrew Cooper told the debate on BBC2's Daily Politics that action on climate change had been "feeble".
UKIP's Roger Helmer said: "I do not believe that the changes in climate are substantially caused by human activity."
He also insisted that it was not something voters were particularly interested in.
"How many people on the doorstep have raised the issue of climate change?" he said.
"It doesn't mean it isn't true but it's a speculative proposition. There's been no further global warming for 18 years."
But Mr Hancock said changes in the climate were "highly likely to be manmade".
He said he would be open to fracking in his own constituency, adding: "I would be open to have shale gas in any part of the country so long as it was explored for in a way that was careful and cautious.
"It's important we do this."
'Not liking Mick Jagger'
Mr Hancock said he thought the expansion of solar energy was superb, but warned that other forms of renewable energy risked destroying the environment.
"Environmental policy is about the beauty of our green and pleasant land. Putting onshore turbines in the wrong places where they are not wanted is not acceptable to local communities and we need to tackle that while supporting other renewables and low carbon," he said.
But Mr Davey compared Mr Hancock's support for renewables but not for onshore wind to "saying you like the Rolling Stones and not liking Mick Jagger".
Ms Flint said Labour would continue to support the development of renewable forms of energy.
"There are costs to this, but let's remember on our bills the green levy only amounts to £60 of an average bill of £1,300," she said.
"But it's about recognising what are the costs if we don't move to cleaner energy. It's important to get this balance right."
Mr Cooper said: "We need to invest in insulating over nine million new homes. We need Greens in Parliament to push for real commitment on climate change."