The latest China-United States statement on enhancing climate cooperation has injected strong momentum into global efforts to make progress at the upcoming 28th Conference of the Parties to the United Nations Framework Convention on Climate Change, or COP28, experts said.

They said the statement, which vows to put into operation a working group that the two nations decided to establish in 2021, has laid important foundations for regular climate communication between the world's two largest economies and carbon emitters.

The Sunnylands Statement on Enhancing Cooperation to Address the Climate Crisis was made public following a meeting between China's Special Envoy for Climate Change Xie Zhenhua and US Special Presidential Envoy for Climate John Kerry in Sunnylands, California, from Nov 4 to 7.

The statement has especially highlighted Sino-US cooperation for COP28, which will be held in Dubai, United Arab Emirates, from Nov 30 to Dec 12 and mark the conclusion of the first Global Stocktake.

The statement emphasized that the stocktake is "a vital opportunity for the parties to reflect on ambition, implementation and cooperation".

"Both countries are committed to working with each other and with other parties to adopt a consensus Global Stocktake decision," it noted.

The decision "should reflect that substantially more ambition and implementation on action and support will be needed to achieve the Paris Agreement's goals, recognizing different national circumstances", it added.

The statement also said that China and the US are committed to furthering their dialogues, efforts and collaboration to support the UAE presidency for the success of COP28.

China and the US, with the UAE, will invite countries to attend a Methane and Non-CO2 Greenhouse Gases Summit at COP28, it said.

Emphasizing that the statement is a result of a joint endeavor for a common goal, Wang Yi, a member of the Environmental Protection and Resources Conservation Committee of the National People's Congress, China's top legislature, said he expects the document to play a positive and enabling role in helping COP28 make progress.

Wang also welcomed the two nations' decision to put into operation the Working Group on Enhancing Climate Action in the 2020s.

In a joint declaration made at COP26 in 2021 in the United Kingdom, the two nations decided to set up the working group as a mechanism that "will meet regularly".

However, the efforts were disrupted because of a controversial visit to the Taiwan region in August last year by Nancy Pelosi, then speaker of the US House of Representatives, after which China halted its climate talks with the US.

The statement on Wednesday said that the working group will focus on areas including energy transition, methane, circular economy and resource efficiency, low-carbon and sustainable provinces, states and cities, and deforestation, as well as any further topics that are agreed upon.

The working group is co-led by the two nations' special envoys on climate change, according to the statement.

The working group's going into operation "will lay foundations for regular, institutionalized Sino-US climate communication in the future", Wang said.

Dimitri de Boer, regional director for Asia at the environmental law organization ClientEarth, said that the statement is "pretty rich in content" and represents "substantive progress".

"First of all, it's a great sign that the US and China release a joint statement on climate action, at a time when President Xi Jinping and (US President Joe) Biden are meeting, and ahead of COP28," he said.

It also reaffirms the commitment of the world's largest economies to climate action, he added.

De Boer especially highlighted the importance of the part of the statement regarding subnational cooperation.

China and the US will support climate cooperation among states, provinces and cities in areas including the power, transportation, buildings and waste sectors, the statement said.

Both sides will help subnational governments, enterprises, think tanks and other stakeholders actively participate in the cooperation, it added.