Signal US Climate Alliance and Climate Mayors Launch Joint Partnership at Climate Week NYC

Summary

Governors and mayors from the U.S. Climate Alliance and Climate Mayors announced a joint partnership at Climate Week NYC on September 22, 2026. The partnership is meant to strengthen climate cooperation among states and cities outside the federal government. The Alliance is a bipartisan group of 24 governors whose states account for about 60% of the US economy and 55% of its population. Boise Mayor Lauren McLean, who chairs Climate Mayors, and Delaware Governor Matt Meyer, the Alliance co-chair, led the announcement, while New York Governor Kathy Hochul joined by video. The step comes as federal climate policy continues to be rolled back. It also coincided with the 2026 Urban 20 Mayors Summit on September 19-21, which gathered 25 mayors from 34 G20 cities.