By Gary O' Donoghue
Political correspondent, BBC News, Liverpool
The Green Party has launched a fierce attack on the main political parties for a "total lack of delivery" on environmental issues.
Sian Berry says the government's plans are failing
In a speech to the party's conference in Liverpool, Principal Speaker Sian Berry, said there was a "yawning gap" between words and actions.
Labour, the Tories and the Lib Dems all claim to have made the environment their top priority in recent months.
On Thursday, the Tories published a 500 page report on future green policies.
Among the ideas - which leader David Cameron has said could be in the party's next manifesto - are a halt to airport expansion and tax increases on short-haul flights.
Measures to combat climate change are also expected to top the agenda at the Lib Dem conference, which gets under way in Brighton on Sunday.
Labour plans to set legally-binding targets for carbon emission reductions for each five-year period to 2050.
But Ms Berry, in a keynote address at the Green Party conference, said the government's environmental policies were "falling down around their ears on a weekly basis".
She added: "Gordon Brown thinks you should solve climate change by changing your light bulbs. We think you should solve climate change by changing your government."
And she attacked what she described as the "sinister and cynical neo-liberals" in the Conservative shadow cabinet who were already shouting down the "handful of well-meaning souls" who had produced the party's Quality of Life review.
The Greens believe the other parties do not go far enough when it comes to tackling climate change.
Among their policy proposals include a complete moratorium on airport and road expansion; free home insulation for all; a reintroduction of the fuel duty escalator, and personal carbon allowances.
The party has seen its representation on local councils grow in recent years, but there has not been the breakthrough at Westminster that many Greens had hoped for.
It is now targeting three seats at the next general election - in Brighton, south London and Norwich.
But like many smaller parties, it wants to see proportional representation brought in, which would give it a much better chance of winning seats in parliament.