John Kerry: world leaders must step up to avoid worst impacts of climate crisis

US envoy uses landmark speech in London to make impassioned plea for unified global effort

The world still has a chance of staving off the worst impacts of climate breakdown but only if governments step up in the next few months with stronger commitments on cutting greenhouse gas emissions, the US envoy for climate change has said.

John Kerry, appointed by Joe Biden to spearhead the US's international efforts to tackle the crisis, urged all large economies to come forward with new plans to cut emissions before the Cop26 UN climate talks in Glasgow this November.