Putting a tax on meat, ending the sale of petrol and diesel cars within a decade and upgrading the energy efficiency of every home in the UK are among the eye-catching green promises from the political parties fighting for voters’ backing in the general election.

Others include zero-emission railways and a £640m Nature for Climate fund to restore the natural world and help fight the climate emergency. These pledges are in the answers given to a series of questions put to the main parties by the Guardian to draw them out on specific key issues.

There was unanimity on just one of the questions posed: all parties said they would give financial support to rewilding projects to enable the recovery of wildlife. A recent report found populations of the UK’s most important wildlife have plummeted by an average of 60% since 1970.

The Conservatives said they would set aside £640m for a Nature for Climate fund, suggesting some of the money would go to rewilding. Labour said it would create 10 new national nature parks and rewild our 10 existing national parks.

However, the Tories were isolated on other issues. They alone did not express support for the thousands of young people striking for climate action: “We don’t support students losing out on their education, though we recognise and respect the passion.”

Labour backed both the school strikers and Extinction Rebellion. “Absolutely,” said a spokeswoman. “This year saw the blossoming of a global movement calling on politicians to wake up. We have turned its demands into detailed, credible plans for real change.”

The Conservatives were also alone in not committing to use planning law to actively support onshore wind and solar farms, saying local people must have the final say on projects.

That distinction was reflected in a Friends of the Earth assessment of the political parties published on Friday, in which the Conservatives lagged significantly behind Labour, Greens and Lib Dem on climate and nature issues. Out of 45 possible points, Labour scored 33, the Greens 31, and the Lib Dems 30. The Conservatives scored 5.5.

Another difference was the date set for the end of sales of petrol and diesel vehicles, which drive global heating and illegal levels of air pollution. The Liberal Democrats, the Greens and Labour all said 2030, with the Scottish National party saying 2032. The Tories said 2040, but said they are consulting on whether this can be brought forward. On air pollution, clean air zones that ban or charge polluting cars in urban centres were backed by Labour, the Lib Dems and the SNP.

The climate crisis is the biggest issue the UK faces, according to Labour, Lib Dems and Greens, while the Conservatives said it is “one of the biggest issues facing the world”.

Flying is one of the toughest sectors in which to cut emissions and the Lib Dems and Greens were clear: they would stop all airports expanding. Labour and the SNP said any expansion must pass climate tests. The Tories mentioned noise and air pollution requirements, but not climate.

Slashing UK transport emissions is key to fighting the climate emergency. They have barely fallen since 1990 and make up a third of all carbon pollution. Three parties pledged to spending more on public transport, walking and cycling than on roads: the Conservatives, Greens and Lib Dems. Labour said it would reinstate 3,000 municipal bus routes, giving under-25s free bus travel and nationalising the railways. The SNP said it was committed to making Scotland’s railways zero emission by 2035.

Houses and business premises produce 40% of emissions and Labour and the Lib Dems say they would spend billions on making every home in the UK more energy efficient, saving households about £500 a year in energy bills. The Tories will focus on 2.2m disadvantaged homes, as well as schools and hospitals.

The UK’s electricity emissions have halved since 2010, as coal burning has fallen to near zero. But the parties are split on the need for new nuclear power stations. The Conservatives and Labour say yes, the Greens, Lib Dems and SNP say no.

Only the Greens say they would set a date for the last new licenses for oil and gas exploration in the North Sea – 2024. The other parties say they would set up plans to ensure good livelihoods for hundreds of thousands of affected people during the transition to a net zero economy. Labour says its £11bn plan would be funded by a tax on the oil and gas companies.

The heavy impact of intensive meat production on the environment has become clear in recent years, and the Greens say they would phase in a tax on meat and dairy products over the next 10 years, with revenues used to help farmers move to more sustainable production. Labour would ask Public Health England to review dietary health guidelines for meat and dairy consumption, while the SNP said it had already set maximum limits for red processed meat in school meals.

All parties committed to maintaining food, farming and environmental standards after Brexit, in some cases by simply remaining in the EU (Greens, Lib Dems, SNP). Labour said its new Brexit deal, which would be put to a referendum, would protect the environment. The Conservatives, who back leaving the EU, said: “In all of our future trade negotiations, we guarantee that we will not compromise on our high environmental protection, animal welfare and food standards.”

You can read the full answers on these and other issues here.

The Brexit Party did not provide answers to the questions, but directed the Guardian to its “contract with the people”.

• This article was amended on 9 December 2019 to remove a reference to Labour being the only party to support Extinction Rebellion and the school strikers. The Green party did also.