Recent carbon and climate neutrality commitments from a growing number of countries and regions —China, the EU, Japan, South Africa, South Korea, the UK, and the U.S. — represent a sea change in global momentum for tackling climate change.

But target setting, while important for anchoring expectations, is only an initial step. The next steps will be more challenging: translating mid-century targets into nearer-term policy actions that are consistent with longer-term goals, and then beginning to measure progress. As the world’s largest emitters and economies, the U.S. and China will need to play leading roles in taking these next steps.

In both countries, much of the momentum for next steps lies at a state-provincial level, rather than at a national level. In the U.S., broad federal policy or spending on climate change does not yet have majority Congressional support, which means that the more than 10 states that have set mid-century targets for greenhouse gas emission reductions will need to continue to drive the transformations in energy systems, buildings, transportation, industry, waste systems, and working lands necessary to meet long-term emission reduction goals. In China, the central government has tasked provincial and municipal governments to develop plans to comply with national mandates for carbon peaking and neutrality.

The strengths of this “bottom-up” approach to developing climate policies are that it allows states-provinces and cities to move at different speeds in different sectors, encourages local experimentation, and promotes buy-in by allowing local governments to determine their priorities and resolve their tradeoffs. The challenge in both countries will be how to coordinate among and balance national, state-provincial, and municipal policy.

As they plan for transitions to carbon neutral economies, state-provincial and municipal government agencies in the U.S. and China will face three key questions: (1) What should be the pace and scale of technology change in different sectors? (2) How can costs be equitably shared? and (3) What can and should be done through local initiatives, versus relying on national policy?

There is tremendous potential for partnerships between states-provinces and cities in the U.S. and China to address these questions. The value of these partnerships is rooted in the shared nature of the challenge but also, as we argue in a recent report, the shared nature of many of the solutions. As they have been historically, partnerships between governments can be supported and complemented by collaboration among universities, research institutes, and non-profits.

U.S.-China subnational partnerships and civil society collaboration should prioritize filling capacity and information gaps through three activities:

• Technical assistance – supporting China’s provincial and municipal government agencies to develop the technical and organizational capacity to plan for how they will meet carbon peaking and neutrality goals. 
• Regular dialogue – providing a forum for regular dialogue and exchange on policy design, the development of common milestones to gauge progress, and implementation experience.
• Benchmarking progress – setting up the information systems to track emerging policies and progress against key milestones.

With continued challenges in the U.S.-China bilateral relationship, subnational partnerships focused around these activities can play an important role in sustaining global momentum for reducing greenhouse gas emissions to net zero levels by mid-century.