California Governor Jerry Brown says like-minded US states should band together to act on climate change if Donald Trump does indeed pull the US out of the Paris Climate deal.

"Yes, he's making this announcement," Governor Brown told Politico.  "But the rest of the world is against him.  California is against him.  New York is against him.  We are for sensible, scientifically based climate action."

President Barack Obama pledged the United States' cooperation in the deal which seeks to reduce greenhouse gas emissions by as much as 28 percent below its 2005 levels by 2025.  Trump has repeatedly claimed that Global Warming is a Chinese hoax, and campaigned on quitting the Paris deal.

But while this has been going on, Jerry Brown has recruited 170 sub-national governments in 33 countries to join the "Under2 Coalition", which sets more ambitious goals than the Paris accord.  National governments including Sweden, Mexico, France, and the UK have endorsed the group's goal of reducing greenhouse gas emissions 80 to 95 percent below 1990 levels by 2050. 

"And through Trump's outrageous action, the contrary movement is galvanized, and we're mobilizing people, states, provinces and working with other countries to move in a direction that is sustainable and is compatible with what we know we must do to survive," Brown said.

Brown heads to China to attend an international climate summit, and push climate and clean-energy policies in Chengdu, Nanjing, and Beijing.

China has already signaled it is ready to take the lead that Trump would abandon; while Trump is expected to proclaim he's abandoning the future on Thursday, China and the European Union are planning parallel announcements about the Paris climate agreement saying it is "an imperative more important than ever".