Kerry urges China to help solve climate challenge

"As a large country and economic leader and now the largest driver of climate change, China absolutely can help lead the world to success by peaking and starting to reduce emissions early during this critical decade of 2020 to 2030," Kerry said in a speech in London.

The former US secretary of state and senator compared the global fight against climate change to World War II, saying: "This test is now as acute and existential as any previous one."

"The world order that exists today didn't just emerge on a whim," he said. 

"It was built by leaders and nations determined to makes sure that never – never – again would we come so close to the edge of the abyss."

But without "sufficient reduction by China", the current goal of limiting warming to 1.5 degrees was "essentially impossible," Kerry added.

Britain is due to host the COP26 climate summit in Glasgow in November, which will gather negotiators from 196 countries and the European Union, along with businesses, experts and world leaders.

The summit marks a "pivotal moment for the world to come together to meet and master the climate challenge," the US envoy said. 

"Glasgow is the place, 2021 is the time and we can, in a little more than 100 days, save the next 100 years.

"Above all we need to provide action, and we need to do it now, because time is running out," he added. 

The world must build on the Paris agreement reached in 2016, because "even if every country, fulfilled its initial promises... the temperature of this planet will still rise by upwards of 2.5 or three degrees centigrade", warned the US politician.

He called for a global effort to cut emissions of greenhouse gasses by at least 45 percent by 2030, as the first step to net zero emissions by the middle of the century. 

"Let me be clear, we are not saying that every country must, will or can do the same thing, we are saying every country can do enough," he said.