Editor's note: This piece was originally published by Nature as a Correspondence article on October 25, 2022. https://www.nature.com/articles/d41586-022-03404-1

As the governments of China and the United States stall over climate cooperation, subnational entities — including states, provinces, cities and universities — are pressing forwards and finding common ground. They are uniquely positioned to test, accelerate and form partnerships on new ideas and policies.

They are collaborating on phasing out coal, for example, because the largest coal-producing US states and Chinese provinces share similar socio-economic, employment transition and environmental challenges, and so could benefit from working together on strategies and solutions. Shipping is another area for partnership: the ports of Los Angeles, California, and Shanghai in China are cooperating with one another to transition to zero-carbon fuelling of ships by 2030 under the Green Shipping Corridor initiative (go.nature.com/3d4xcxo).

As noted in the US–China Joint Glasgow Declaration (go.nature.com/3f7nqk3), subnational entities are aiming to reduce methane emissions through measurement programmes and incentives — particularly in the agricultural and waste sectors — and to improve data collection and monitoring. Subnational technical exchanges are also under way on climate resilience, infrastructure investment, zero-carbon building standards, transportation policies, low-carbon fuel standards, battery supply-chain improvements and electric-vehicle deployment.