While COP30 gets underway in Brazil - Donald Trump is ripping up climate policy, blasting his allies for falling for what he calls the ‘world's greatest con job’ and trying to get big business to follow his lead - and yet in New York, Zohran Mamdani - a left-wing populist unafraid to tout a green agenda - has just won the mayoral race and in the UK, the Green Party has surged under Zack Polanski.

So is the direction of travel really a climate rollback - or is a new left preparing to claim power and reclaim the climate argument? 

With me, from the COP in Belém, is our Chief Correspondent Alex Thomson - and in London, the financial journalist and author Andrew Ross Sorkin, whose new book 1929 investigates the Wall Street crash.