The King has urged delegates at the Cop31 climate summit to turn ambition into action, warning the need has never been “more urgent”.
World leaders are meeting in Antalya, Turkey, at the UN’s annual international conference to set out agreements on how to tackle climate change.
Charles, who spent decades campaigning on green issues, stressed that “our children and grandchildren” will judge us, not by the promises we made, but on what “we chose to do”.
The monarch said in a written message released on Wednesday: “As the world gathers for Cop31, I can only hope that this same spirit of partnership and common purpose can help inspire the collective action that our planet – and future generations – so urgently need.
“I therefore urge you, and all who join you in Antalya, to meet this moment not only with ambition, but with the determination to turn that ambition into action. This must be Cop31’s legacy.
“Our children and grandchildren will not judge us by the promises we made, but by what we chose to do.”
The King added: “As we are all only too aware, across the world communities are already enduring severe heat, floods, droughts, wildfires and storms.
“Recent events have reminded us, sometimes in the most tragic manner, that climate change is not a distant threat.”
He sent his “warmest good wishes and encouragement” to all those taking part, telling them: “For more than five decades, I have sought to draw attention to the interconnected threats of climate change and the destruction of Nature, and the impact on our livelihoods and communities.
“The need for action has never been clearer – nor more urgent.”
The King delivered the opening address at Cop28 in Dubai in 2023, while his son the Prince of Wales spoke on his behalf at Cop30 in Brazil in 2025.
Read MoreClimate crisis threatens national security for all, Ed Miliband tells Cop31
How a year of extreme heat around the world is reshaping conversations at Cop31
How Turkey’s drive to expand a major coal plant is polluting its climate push
