Biden heads to crucial climate talks as wary allies wonder if US will deliver

President faces challenges to reassert US credibility after Trump but critics say Biden's actions have yet to match his words

With no major climate legislation firmly in hand and international allies still smarting after four bruising years of Donald Trump, Joe Biden faces a major challenge to reassert American credibility as he heads to crucial UN climate talks in Scotland.

The US president, who has vowed to tackle a climate crisis he has described as an existential threat" to civilization, will be welcomed to the Cop26 talks with a sense of relief following the decisions of his predecessor, who pulled his country out of the landmark Paris climate agreement and derided climate science as bullshit".