The three main parties are failing to provide "consistent leadership" needed on green issues, say campaigners.
More needs to be done on domestic climate change policies, the report says
The Green Standard - a report by nine leading environmental groups - looks at each party's commitments and actions.
The Lib Dems were rated highest, getting three "green lights" indicating approval of their policies. Labour got one and the Tories none.
The report welcomed the issues' higher profile among MPs but said leaders needed the "courage" to take action.
Greenpeace, Friends of the Earth, WWF, the RSPB and the Campaign to Protect Rural England were among groups involved in drawing up the report.
Language of urgency
It assessed parties on six issues - international and domestic action on climate change, green living, the national environment, planning and green taxes and subsidies - and marked them using a traffic light system.
The Lib Dems scored well on domestic climate change policies, making it easier for people to go green and on green taxes. Labour was awarded a "green light" for its international leadership on climate change.
But despite the "urgency in the language and aspirations of all three parties in relation to climate change", it found "far less interest" in protecting the countryside and biodiversity.
The group pointed to Prime Minister Gordon Brown's plans for three million new homes by 2020, partly helped by changes to the planning system, and the failure to commit parliamentary time to discuss a marine bill.
The government is also criticised for its record on carbon emissions and tackling climate change at home - despite strong leadership internationally.
The Lib Dems are praised for embracing the fight against climate change - the group describes their recent "Zero Carbon Britain" report as "a bold and far reaching strategy" but says the party also appears "uninterested" or uncommitted to protecting the natural environment.
The Conservatives, who ran their 2006 local election campaign on the slogan, "Vote blue, go green", are praised for raising the profile of the environmental cause - but criticised for having "very few policy positions".
While the report notes that the party is still going through its policy review process, it says there is "considerable uncertainty" around its future direction and says the gap between "Conservative aspirations on the environment" and policy commitments was "stark".
Campaigners were "extremely concerned" about the proposals in the Tories' Competitiveness Commission report for more road building and airport expansion.
Campaigners are alarmed by plans for airport expansion
Director of the Green Alliance, Stephen Hale, said party leaders had to show "greater courage and commitment".
"It is very disappointing that none of the three main parties are yet providing the leadership and action we need," he said.
"The environmental ambitions of the parties are very welcome but all three must close the gap between rhetoric and delivery in the run-up to the next general election."
The Liberal Democrats welcomed the report, which they said showed they were "three times as green" as other parties.
Environment spokesman Chris Huhne said: "Despite all their warm words, it is telling that the Tories fail to get a single green light. Moreover, they are still divided between those like John Gummer who want to go green and those like John Redwood who do not."
A Labour Party spokesman said the party welcomed a "healthy debate" although it did not agree with all the group's assessments.
"The key difference between Labour in government and the other parties is that we are getting on and delivering while the other parties only have to make promises," he said.