Tonight's historic climate debate ... exposed the disregard for this existential crisis of those who couldn't be bothered to turn up.
Party leaders have debated cutting emissions, tree planting and the future of flying - and their own personal actions to help the environment - in the first televised climate debate.
Parties are vying for the votes of those concerned about the environment in what has, despite subjects such as Brexit and the NHS, been dubbed by some as "the climate election".
But Prime Minister Boris Johnson and the Brexit Party's Nigel Farage snubbed the Emergency On Planet Earth debate on Channel 4 News.
Their absence was represented by two circular ice sculptures engraved with maps of the world which stood melting on stage throughout the hour-long programme.
Labour leader Jeremy Corbyn, Liberal Democrat leader Jo Swinson, Scottish First Minister and SNP leader Nicola Sturgeon, Plaid Cymru's leader Adam Price and Green co-leader Sian Berry debated the level of ambition for cutting emissions to net zero.
The Conservatives, who sent Michael Gove to the debate though he was not allowed to take part as he is not the party leader, have said they will deliver on the new legal target to deliver net zero emissions by 2050.
But Mr Corbyn said the Government was off track to meet that goal and that everything possible must be done to reach a 2030 net zero emissions target.
The Labour leader said: "I think we have to do everything we can to get to a 2030 net zero emissions target and we do that by investment in green energy jobs, solar, wind and wave power, we do that by creating jobs and transforming our energy consumption, by retrofitting homes to make them environmentally sustainable."
Ms Sturgeon said Scotland's targets, to cut greenhouse emissions to zero by 2045 and be carbon neutral by 2040, are "the toughest in the world" and that they are going "beyond what the Committee on Climate Change has said".
Also calling for the 2030 target, Mr Price said it was a shame that Labour's manifesto only pledged to get "the majority" of emissions down by 2030, and called on a future UK government to "show the same level of ambition" as other countries.
Ms Swinson said Liberal Democrats "believe it is absolutely possible to get there by 2045".
Ms Berry defended the Green Party's 2030 net zero target against questions it was not credible, saying: "We have to do what the science demands, not what is politically convenient."
The leaders went on to debate how to get to their targets, looking at the role of switching to a more plant-based diet, whether there should be frequent flyer taxes, improving public transport and helping people make their homes more energy efficient.
In what was perhaps the only real swipe at the absent Tories, Ms Swinson criticised them for not bothering to turn up and for cancelling the zero carbon homes target to make new homes highly energy efficient.
When quizzed on the personal changes they were making to help the environment, Mr Price said he and his partner had switched to using reusable nappies for their young son.
Mr Corbyn said he had only switched on the heating last week and had turned it off again quickly, adding "I'm quite miserable on this basis, but I don't like to see the waste of energy".
December's General Election comes at the end of a year marked by mass protests and rising public concern over the climate and wildlife crises.
A poll taken shortly before the election was called revealed that the majority of people said climate change would influence how they voted.
RSPB's head of conservation Martin Harper said: "This debate has provided a much-needed opportunity to scrutinise some of those leaders vying to be elected on how they will deliver action at the unprecedented scale required to avert disaster."
Rebecca Newsom, head of politics at Greenpeace UK, said: "Tonight's historic climate debate laid bare the ambitions of the leaders who took part, and exposed the disregard for this existential crisis of those who couldn't be bothered to turn up.
"There was clear acknowledgement from all leaders that transformation is needed across every sector of our economy, with strong action plans to green our energy system and homes.
"But on sectors that require bigger personal lifestyle change, such as flying and reducing meat consumption, the leaders dodged the subjects faster than a frightened calf."
Emily Beament is the PA environment correspondent.