GLASGOW - China and the United States on Thursday vowed to work together to accelerate climate action this decade, separately announcing a surprise pact on global warming, which is already causing disasters across the world.

The joint declaration came as the crunch COP26 summit in Glasgow entered its pivotal final days, with negotiators wrestling over ways to limit global warming to 1.5-2 degrees Celsius compared to preindustrial levels.

“This document contains strong statements about the alarming science, the emissions gap, and the urgent need to accelerate action to close that gap,” US special envoy John Kerry told reporters.

“It commits to a series of important actions now this decade when it is needed.”

The plan is light on concrete targets but heavy on political symbolism at a conference that began with the US and China.  “Both sides recognise that there is a gap between the current effort and the Paris Agreement goals so we will jointly strengthen climate action,” Xie said.

Chinese President Xi on Thursday stressed the need for cooperation between the two superpowers, who together account for nearly 40 percent of all carbon emissions.  “All of us can embark on a path of green, low-carbon sustainable development,” he told a virtual business conference on the sidelines of the Asia-Pacific Economic Cooperation summit.

“Together, we can usher in a future of green development.”  A document outlining the agreement includes a focus on lowering methane emissions, which Kerry described as the “single fastest and most effective way to limit warming”. It also says the two sides will meet regularly to “address the climate crisis”. The document stresses the need to boost efforts to fight climate change in the short term -- scientists have warned that slashing emissions before 2030 is crucial for halting catastrophic warming.

The declaration said both countries “recognise the seriousness and urgency of the climate crisis”, especially during the “critical decade of the 2020s”.