There is now an excellent chance that the Paris Agreement on Climate Change, adopted by acclamation at Le Bourget last December, will enter into force before the end of this year following its ratification by China and the United States, the world's two largest emitters of greenhouse gases. All it needs to cross the legal threshold is formal acceptance by 55 countries collectively responsible for at least 55 per cent of global emissions. So far, 26 countries accounting for 39 per cent of emissions have already signed up, and it is reasonable to expect a surge in the coming months, especially as UN secretary general Ban Ki-moon is holding a valedictory "special event" at its headquarters in New York later this month, to strengthen international focus on the climate and what needs to be done to protect it.
The communiqué issued earlier this week after the G20 summit in Hangzhou, China, placed climate change at centre stage of the global political agenda and sends a strong signal for all 195 countries in the world to join the Paris Agreement as soon as possible. There is no reason for delay given that every month for the past year or more has been breaking temperature records and the world is now warming at a speed not experienced at any time within the past 1,000 years, according to Nasa's chief climate scientist, Gavin Schmidt. With the average global temperature peaking at 1.38 degrees Celsius above pre-industrial levels, he warned it was now "very unlikely" that the world would achieve the central objective of the Paris Agreement to limit global warming well below 2°C and as close to 1.5°C as possible.
Accumulating scientific evidence that Earth is entering uncharted waters, with potentially devastating consequences for humanity, should spur decisive action at the highest levels. Clearly, the dangers are recognised by US president Barack Obama and his Chinese counterpart, Xi Jinping. Mr Obama, with less than five months left in office, has an eye on his legacy, although it remains to be seen whether this is undone if Donald Trump succeeds him in November's US presidential election. Mr Trump has shown no understanding of what's at stake. Mr Xi wants to clean up the chronic air pollution in China's cities, which is why coal burning there has peaked, and also sees an opportunity for Chinese companies to become world leaders in renewable energy.
The fact that the US and China are both parties to the Paris Agreement (after they had shunned participation in the 1997 Kyoto Protocol) and have now ratified it “signals a new era in global efforts to address climate change”, according to Jennifer Morgan, executive director of Greenpeace International. Paris provides the framework for much more ambitious action over time, and one of the urgent priorities – flunked yet again by the G20 – must be a rapid phase-out of worldwide subsidies for fossil fuels.