President Biden campaigned on a promise to have the United States rejoin the Paris Agreement. On inauguration day, he signed an executive order doing just that, which should become effective on February 20, 2021. United Nations Secretary General Antonio Guterres welcomed the U.S. back, saying “We look forward to the leadership of United States in accelerating global efforts towards net zero.”
China also noticed. Speaking through action, China re-appointed Xie Zhenhua, a long standing negotiator who played a major role in structuring and writing the Paris Agreement. Just as Biden has appointed John Kerry (also a key player in Paris in 2015) the Special Presidential Envoy for Climate, the Chinese Foreign Ministry appointed Xie as special envoy for climate affairs on February 4th (my birthday, so I missed it!). Xie has been out of the international climate negotiations for the last two years, and is well past the official retirement age.

Li Shuo of Greenpeace in Beijing sees Xie’s appointment as “clearly a tailored move toward the U.S., an effort to ensure the diplomatic channels are there. With his experience and contacts, Xie’s appointment will at least help reduce transactional cost in China’s climate diplomacy.”
Xie himself, as head of Tsinghua University’s Institute of Climate Change and Sustainable Development, pointed out last year that the U.S. and China have continued to work together despite the Trump Administration’s lack of engagement in the international climate negotiations.
“In fact, we have never lost contact with state governments, universities and enterprises in the U.S., we have been maintaining effective cooperation. Regardless of domestic situation in the U.S., we are always willing to carry out cooperation.”