Donald Trump has made sure that, on climate change, the country he leads is the Disunited States of America. In an act of open defiance, five days after the president withdrew the US from the Paris climate agreement, the governor of California, Jerry Brown, met China’s president, Xi Jinping, to discuss cooperation “in dealing with the larger problems of humanity”—a.k.a. climate change.

California is one of 12 states that have joined hands under the United States Climate Alliance, which launched the day of Trump’s Paris announcement and which has pledged to meet or exceed the targets for reducing emissions that the international climate agreement set in December 2015. Mayors of more than 200 US cities are also part of the alliance, and six other states have shown an interest in joining. Brown was one of those who led the creation of the alliance; he had made public his intentions to start a “countermovement” against Trump’s environmental policies back in March.

Xi is not known for setting up meetings with state-level politicians, but Trump’s withdrawal presents him with an opportunity to start leading the world on climate action. “California’s leading, China’s leading,” Brown told reporters (paywall) at the energy conference where he met Xi. “It’s true I didn’t come to Washington, I came to Beijing.”

Brown has spent the last few days touring China to talk about efforts to reduce carbon-dioxide emissions and promote green technologies—both of which Trump has signaled he doesn’t care about. China would also like to learn from California’s experience of running a cap-and-trade program, which puts a price on carbon emissions, and which China is looking to deploy across the country later this year.

“Nobody can stay on the sidelines,” Brown said. “We can’t afford any dropouts in the tremendous human challenge to make the transition to a sustainable future.”

In what looks like a growing divide between the states and the federal government, the New York Times reported that, though US energy secretary Rick Perry was at the conference, it doesn’t appear that he met Xi. Perry talked about carbon capture and storage (CCS), a technology that can be bolted on top of a coal-power plant to reduce its emissions.

CCS is “a critical low-carbon technology that we must deploy to reduce emissions at the required scale from coal and gas-fire power plants, and the only option for decarbonizing high-emission process industries,” Perry said. Trump’s budget cuts federal funding for the technology.