Xi Jinping (China’s President) and Barack Obama (US President) shakes hand with U.N. Secretary-General, Ban Ki-moon as they ratify the Paris Agreement. Photo credit: Reuters / How Hwee Young / Pool.

By Anders Lorenzen

The world’s two largest greenhouse gas emitters, China and the US, have just made their biggest ever commitment towards tackling climate change by ratifying the Paris Agreement.

The ratification came just days before China hosted the world’s 20 largest economies at a G20 meeting in Hangzhou, Zhejiang.

On Saturday the world’s two largest economic powers submitted their plans to join the agreement to the delight of U.N. Secretary-General, Ban Ki-moon who was in China to witness the announcement.

China and the US were hardly among the quickest nations to ratify. 23 countries had already done so before them, though those countries only represent 1.08% of the world’s global emissions.

The move from the two countries to ratify the agreement is significant as China represents over 20% of global emissions, while the US accounts for 17.9%. It is now expected that India, which is responsible for 4.1% of the world’s emissions, will be next. The latest update on the Paris Agreement ratification tracker tells us that 26 countries have now ratified. For the agreement to come into force , another 55 countries are needed, as the global emissions covered would need to increase to 55%, (currently at 39%).

But it also provides embarrassing figures for the western world`s reputation, in that Norway is the only country in Europe to have signed up so far. There are now serious calls for many EU countries to speed up their ratification process.

President Obama agreed to ratification to protect his climate change legacy. His presidency ends in January 2017, and it is a legacy Hillary Clinton has promised to continue should she become the next US President. However, the majority of the Republican Party oppose the Paris Agreement. And Republican presidential candidate, Donald Trump, has promised that if he were to be elected he would cancel the agreement. Obama is keen to speed up the process to increase the chance it could come into the force by the end of this year, a lot earlier than originally expected. This would make it much harder for Trump to opt out should he, against the odds, become the next president. Countries that ratify the deal will have to wait for three years after it has gone into legal force, before they can begin the process of withdrawing from it.

Senior Obama adviser, Brian Deese, said that the joint declaration should be a signal to other countries to ratify: “The signal of the two large emitters taking this step together and taking it early, far earlier than people had anticipated a year ago, should give confidence to the global community, and to other countries that are working on their climate change plans, that they too can move quickly and be part of a global effort.”

Bill Hare, chief executive of Climate Analytics expects precisely this to happen, adding: “We expect a surge of ratifications around the U.N. Climate week later in September.”

Li Shuo, from Greenpeace, said that he expected the Paris Agreement to come into force before the end of the year: “It now looks like the Paris agreement will enter into force before the end of the year and that will really be like the speed of light, compared to almost all other international agreements.”

But Alden Meyer, international director of the Union of Concerned Scientists, warned against complacency, and he said a lot of hard work lies ahead: “All countries will need to raise the ambition of their commitments under the agreement if we’re to avoid the worst impacts of climate change, and reach a goal of net zero global warming emissions by mid-century,”  he stated.

China and the US have previously disagreed on what climate change actions they individually would take. But in recent years they have walked hand in hand on climate change with commentators arguing that the China – US Climate agreement (agreed in 2014) was the catalyst for achieving the Paris Agreement.