Britain has tasked naturalist David Attenborough with inspiring action to tackle the issue of climate change as its People's Advocate ahead of the United Nations' Climate Change Conference (COP26) in November in Glasgow, Scotland.
COP26 could accelerate measures by the world's biggest polluters to tackle climate change, which activists, scientists and world leaders say could ultimately endanger the planet.
Britain holds the presidency of the conference this year.
Attenborough, 95, the world's most influential wildlife broadcaster, will exhort leaders at events over the next six months to put climate and the protection of nature at the top of their agenda, including at the Group of Seven summit in Cornwall, southwest England, in June, the UK government said on Monday.
He has also been invited to address world leaders and the public at the Glasgow summit, which has been billed as the most important climate meeting since the Paris Agreement in 2015.
"David Attenborough has already inspired millions of people in the UK and around the world with his passion and knowledge to act on climate change and protect the planet for future generations. There is no better person to build momentum for further change as we approach the COP26 climate summit in November," said Prime Minister Boris Johnson.
Johnson, who is keen to burnish his environmental credentials, has said he will push leaders at the G7 summit he will chair to make firm climate commitments.
Attenborough said COP26 had to succeed.
"There could not be a more important moment that we should have international agreement. The epidemic has shown us how crucial it is to find agreement among nations if we are to solve such worldwide problems," he said.
In February, Attenborough told the UN Security Council that climate change is the biggest security threat that modern humans have ever faced.