Responding to climate change requires data-driven coordination. Although numerous climate mitigation and adaptation efforts are underway across different U.S. states, regions, and jurisdictions, there have been limited opportunities to coordinate and integrate these efforts. To address this need, the U.S. Climate Alliance will, over the next year, build the U.S. Climate Alliance Clearinghouse— a website that aggregates climate tools, data, and information for use by policymakers and the public. By facilitating greater regional cooperation, the U.S. Climate Alliance will enhance the capacity of our members to take measurable action independently and collectively to stop climate change.