US and China Formally Join Paris Climate Pact

China and the US have formally ratified a historic climate change agreement drawn up in Paris to cut emissions and fight climate change. Speaking on the eve of the G20 summit in Hangzhou on Saturday, Mr Obama said: “History will judge today’s effort as pivotal.” The US and China are together responsible for 40% of the world’s carbon emissions.

The Paris deal is the world’s first comprehensive climate pact, agreed last December to cut emissions enough to keep the global average rise in temperatures below 2C. It will only come into force legally after it is ratified by at least 55 countries, which between them produce 55% of global carbon emissions.

Erik Solheim, director of the United Nations environment programme, said the ratifications bring significant additional momentum to the drive against global warming.