Politicians must "lead and give people confidence" that the changes needed to reach net zero are "desirable and possible for us all", Sir David Attenborough has said.
Sir David was speaking to mark a year since the publication of the first UK-wide citizens assembly on climate change report and ahead of the the United Nations' climate change conference, COP26, in November.
The report laid out a road map on how the UK could reach net zero by 2050 while being fair to people. It identified education and information, government leadership, and cross-party consensus as key components if success was to be achieved.
The UK is hosting COP26 and will push for an international strategy on reaching net zero. However the UK government's own credibility on climate change has been questioned, with rows over mining and North Sea drilling licences.
And Sky News has revealed how the UK agreed to drop climate commitments from the text of a trade deal with Australia in order to get the agreement signed.
Sir David - the people's advocate for COP26 - said: "The world's scientists have been very clear on what's at stake for mankind if we don't act on climate change.
"Our political leaders now need to lead and give people confidence that all the changes needed to deliver net zero are desirable and possible for all of us.
"Parliament's climate assembly has done a truly remarkable job of highlighting the high levels of public support for climate action up and down this country and given government and MPs an invaluable roadmap of how it can be done.
"We owe the members of the UK public who took part in it a huge debt of gratitude.
"Above all, the assembly has been abundantly clear that greater public participation and fairness is needed at the heart of all climate action and this is therefore a message I hope this government has heard loud and clear and certainly one I plan to share with all world leaders at COP26 in Glasgow."
Sue Peachey, an assembly member from Bath said: "If [Boris Johnson] takes time to inform and work with people who have legitimate concerns, we have shown he should be pushing at an open door."
Darren Jones, chair of the Business Energy and Industrial Strategy (Beis) committee, said the assembly had done Mr Johnson's homework for him.
"But the prime minister and chancellor have so far seemed too scared to be upfront with people about the small changes that we will all need to make in the near future," he said.
"The government must build on the climate assembly's work and urgently bring the public into the debate about what tackling climate change really means, explaining not just why it's necessary but how it'll have a positive effect on people's lives."