Editor’s Note: This is a wrap of several top stories from China for April 23, 2021.

Hong Kong CNN  — 

With Washington rejoining international efforts against climate change under President Joe Biden, the United States and China now have a new area of competition – leading the world in staving off environmental catastrophe.

On Wednesday, Biden hosted a virtual two-day climate summit attended by 40 other world leaders, including Chinese leader Xi Jinping, who just three days earlier criticized the US for “bossing others around” at another forum.

Relations between the US and China have plummeted rapidly in recent years. But compared with technology, trade, geopolitics, defense and other areas of increasingly intense face-offs, climate change is an issue where decoupling is least likely – and allows most room for agreement, cooperation and potentially even joint leadership on the world stage.

China and the US are the world’s two biggest carbon polluters. Together, they account for almost 45% of global fossil fuel emissions that are warming the atmosphere of our planet, according to the most recently available data. China’s emissions nearly double that of the US, although in per capita terms, an American on average is more than twice as carbon polluting as a Chinese citizen.

At this week’s summit, Biden announced ambitious targets for the US, pledging to cut greenhouse gas emissions by 50-52% below its 2005 emissions levels by 2030. The European Union, Canada and Japan also announced their new targets. Xi, meanwhile, reaffirmed his pledge from last summer, vowing to peak emissions by 2030 and eventually achieve carbon neutrality by 2060.

Li Shuo, senior climate adviser for environmental group Greenpeace in Beijing, said it’s difficult to compare the emission cut targets set by different countries, because the baselines of reduction are different.

“The most important thing is not how far the promise was made on paper, but how much it can be materialized in reality,” Li said.

During his speech, however, Xi stressed China’s climate goals are a massive undertaking that surpass those made by its richer, more developed counterparts.

“China has committed to move from carbon peak to carbon neutrality in a much shorter time span than what might take many developed countries, and that requires extraordinarily hard efforts from China,” Xi told other world leaders.

And when it comes to actual implementation, China’s one-party, top-down political system means it is unaffected by election cycles – unlike the US. In a thinly veiled jab at the Trump administration’s withdrawal from the Paris agreement, Xi appeared to underscore this difference, noting that to achieve global carbon neutrality, the world “must maintain continuity, not reverse course easily; and we must honor commitments, not go back on promises.”

The US-led summit is the first such get together for Xi and Biden since Biden took office. Ahead of the event, John Kerry, the US special presidential envoy for climate, met with his Chinese counterparts in Shanghai, where the two sides agreed to cooperate to tackle the climate crisis with urgency.

But while climate cooperation has been welcomed by all sides – and is desperately needed from a global perspective – there are concerns such collaboration might not be able to entirely escape the fallout from other areas of this heated bilateral relationship.

As Xi was addressing Biden’s summit, Chinese state-run tabloid Global Times lambasted a bipartisan push by US lawmakers to counter China in areas of human rights, economic competition and technology, accusing them of “creating confrontation (that) will backfire against the US” and urging Washington to “cast aside its hegemonic dream and Cold War mentality.”

“Such a self-contradicting practice that mixes hostility with a cooperative attitude could impact potential China-US cooperation,” the paper warned.