They were speaking at the Saudi Green Initiative (SGI) ahead of COP26, the U.N. climate conference in Glasgow at the end of the month, which hopes to agree deeper global emissions cuts to tackle global warming. The United States, the world's second biggest emitter, is committed to achieving 'net zero', meaning that it emits no more greenhouse gases than it can capture or absorb, by 2050. But China and India, the world's biggest and third-biggest emitters, have not committed to this timeline. Amin Nasser, chief executive of the state oil giant Saudi Aramco, said it was counterproductive to "demonise" hydrocarbons. He said Aramco aimed to expand its oil and gas production capacity while also achieving net zero emissions from its own operations by 2050. He called for more global investment to ensure adequate crude oil supplies.