John Kerry, the US special presidential envoy for climate, and Sultan Ahmed al-Jaber, president of Cop28, at the climate summit in Dubai on Saturday. Photograph: Sean Gallup/Getty Images The United States and 21 other countries pledged on Saturday at the United Nations climate summit in Dubai to triple nuclear energy capacity by 2050, saying the revival of nuclear power was critical for cutting carbon emissions to near zero in the coming decades. Proponents of nuclear energy, which supplies 18 per cent of electricity in the United States, say it is a clean, safe and reliable complement to wind and solar...