Amid the squabbles, bombast and competing interests, just what can Cop30 achieve?

“It broke my heart.” Surangel Whipps, president of the tiny Pacific nation of Palau, was sitting in the front row of the UN’s general assembly in New York when Donald Trump made a long and rambling speech, his first to the UN since his reelection, on 23 September.

- Fiona Harvey

Whipps was prepared for fury and bombast from the US president, but what followed was shocking. Trump’s rant on the climate crisis - a “green scam”, “the greatest con job ever perpetrated”, “predictions made by stupid people” - was an unprecedented attack on science and global action from a major world leader.

Palau, threatened by rising sea levels, floods and more intense storms, is home to nearly 20,000 people, all likely to be made refugees if global heating surpasses 1.5C for a prolonged period, a likelihood they are desperate to prevent. They know they are just the beginning, the frontline. Around the world hundreds of millions of people’s homes and livelihoods will be destroyed by climate breakdown within decades.

“Our children need hope, they need to be inspired,” says Whipps. “They need to see us coming together to solve problems.” What they got instead was a tirade, disbelief and discouragement.

Whipps’s dismay is felt by vulnerable countries around the world. After years in which it appeared politicians were beginning to act on the climate crisis, a populist tide has swept in, turning back or threatening progress in many democracies.

Trump’s words were just the most extreme expression of a rightwing trend. In the European Union, hard-right political groupings delayed key decisions on emissions targets and are seeking further abandoning of climate action. The UK’s poll-topping Reform party openly embraces denial. In Argentina, Trump’s ally Javier Milei has taken his chainsaw to climate policy as well as the economy.

Yet polls find an overwhelming majority of people - 89% globally - are concerned about the climate crisis and want action. There have been unexpected victories for pro-climate action politicians: Mark Carney in Canada, Anthony Albanese in Australia, and Claudia Sheinbaum - a climate scientist - in Mexico.