An unseasonably hot September sun blazed down from a cloudless blue sky as the UK’s foreign secretary, David Lammy, took to the stage at the Temperate House at Kew Gardens, in west London. The choice of venue was no accident. It was here in July 2021 that the then US special presidential envoy John Kerry made his landmark speech comparing the climate crisis to the ravages of the second world war and vowed to forge a global agreement to “never again come so close to the edge of the abyss”.
That speech set the tone for a successful Cop26 summit in Glasgow three months later, a high water mark of global climate diplomacy and the last time the world looked unified in trying to contain the climate crisis within the relatively safe limit of a 1.5C temperature rise.
