Though the United States is planning to leave the landmark Paris climate agreement, the door for Sino-US climate cooperation remains open, said Kevin Rudd, the former Australian prime minister.

While it is a huge challenge to find a proper manner for climate dialogue between the two major powers, civil society, such as NGOs, could do what the governments could not do, he said.

Rudd, who is also inaugural president of the Asia Society Policy Institute, made the remarks while addressing Energy Foundation China's 20th anniversary celebration in Beijing on Wednesday.

He noted that China and the United States played indispensable roles in making the Paris agreement.

"The Paris agreement adopted in 2015 is important," Rudd said. "But what I want to stress is that the joint statement signed by China and the United States here in Beijing about five years ago is more important, because without the joint statement, there would be no Paris agreement.

"This joint statement marked that the two largest economies and carbon emitters in the world joined hands for the first time to cope with one of the biggest challenges of the planet," he noted.

He also commended China's determination to insist on the Paris agreement when the US decided to withdraw from the treaty. If China also withdraws, the Paris agreement will be meaningless.

"So I want to emphasize that the determined attitude of China on the issue deserves the world's recognition," Rudd said.

US President Donald Trump announced in June 2017 that the US would leave the agreement, and the country began the withdrawal process on Nov 4.

According to the agreement, the withdrawal of signatories will take effect one year from delivery of the notification.

Despite Trump's decision to withdraw, Rudd said he believes that there is still space for the two countries to continue rational cooperation on climate change.

He said he had especially noticed that US Secretary of State Mike Pompeo acknowledged in a statement in October that the US will continue to tackle climate change, reduce carbon emissions and persist in global cooperation.

"This is good news," Rudd said. "It shows that the door remains open for Sino-US cooperation (on climate change), despite that it's still a huge challenge for the two countries to find a proper manner for dialogue."

He said he is delighted to find that there are still many NGOs that continue to work toward creating channels and building bridges to maintain dialogue and cooperation, as shown in many Energy Foundation China projects.

The California-China Climate Institute, which was recently established by the University of California, Berkeley and Tsinghua University, serves as an example of these efforts.

Civil society could do what the governments haven't been able to do, Rudd said.

Warning about the high risk of decoupling China and the US, and referring to himself and Xie Zhenhua, China's special representative for climate change affairs who also attended the ceremony, as old cadres on climate change issues, he said: "As to climate work, the revolution has not succeeded yet, and comrades still need to work hard."