China and the United States pledged Wednesday to work more closely together to fight global warming, declaring the climate crisis "one of the greatest challenges of our time".
The announcement came hours ahead of a summit between presidents Joe Biden and Xi Jinping in San Francisco, further fuelling hopes the two nations can mend relations following years of turmoil over issues including trade, human rights, and the future of Taiwan.
In a joint statement following climate talks in the United States, they pledged to make a success of a crucial UN climate summit starting at the end of this month in Dubai.
And they re-committed to the 2015 Paris climate accord goals of holding global warming to "well below" 2C while pursuing efforts to limit the increase to 1.5C.
"The United States and China recognize that the climate crisis has increasingly affected countries around the world," the statement said.
"They will work together… to rise up to one of the greatest challenges of our time for present and future generations of humankind."
US and Chinese climate envoys John Kerry and Xie Zhenhua met this month at the Sunnylands resort in California in a bid to restart stalled cooperation.
Experts agree that keeping the Paris goals in reach will require an enormous collective effort to slash greenhouse gas emissions this decade.
But that goal is seen as even more challenging in a world roiled by geopolitical storms, including the China-United States rivalry.
The International Energy Agency (IEA) warned last month that "immediate reductions" in methane emissions were needed to limit climate warming.
A broad plan by Beijing last week to control its emissions of gas offered no specific target for reducing them.
But in their joint statement, the two sides agreed to develop their respective methane reduction targets for inclusion in their 2035 emission-cutting plans, known as Nationally Determined Contributions, or NDCs.
- No decoupling -
With temperatures soaring and 2023 expected to become the warmest year in human history, scientists say the pressure on world leaders to curb planet-heating greenhouse gas pollution has never been more urgent.
Countries are set to meet in Dubai later this month for the COP28 summit.
And success at those talks will hinge on agreement between the United States and China -- still at loggerheads over a litany of issues from trade to human rights.
Asked about what he expected from looming talks with Xi, Biden on Tuesday characterised the meeting as a chance to right ties.
"We're not trying to decouple from China. What we're trying to do is change the relationship for the better," Biden told reporters at the White House before heading to San Francisco.
He said he wanted "to get back on a normal course of corresponding; being able to pick up the phone and talk to one another if there's a crisis; being able to make sure our (militaries) still have contact with one another".