The Pittsburgh Climate Initiative (PCI) in Pennsylvania is one of a few local climate programs that is led by a coalition of organizations instead of by government alone. In contrast to a single‐platform, top‐down model, it is headed by a partnership of nonprofit, local government, business, and institutional stakeholders that provides multiple platforms for action. Collaboration both across and within sectors enhances the PCI's overall impact and that of each organization with which it engages. Thus, the PCI has been able to successfully engage Pittsburgh and Allegheny County residents, businesses, governments, and universities in taking measurable actions to reduce greenhouse gas emissions. As a result, the PCI helps to secure the region's economic interests while safeguarding the physical well‐being of its residents. © 2012 Wiley Periodicals, Inc.