This manual provides guidance on how to prioritize and implement the operational changes that allow public health agencies to shrink their climate impact, and it also provides guidance about how to demonstrate a commitment to a healthy future. The following categories are discussed for addressing emissions reductions: Energy; Buildings; Transportation; Food;Purchasing; Waste; and Water. Under each topic, there are specific steps that individual public health departments or organizations can take. For each proposed step, there are estimated capacity needs, cost, and impact of implementation. In recognition that many departments are stretched for human and financial resources, the manual identifies actions that can be implemented immediately at little cost as well as those that may need long-term planning and budget allocation. The manual suggests actions that can occur internally, as well as steps that can be taken for influencing decisions that are out of the control of health departments. Because communication is key to making change either within the office, with your community, or at the state or territorial level, weve included a section with advice on how to address these issues both internally and externally. The concluding section provides a number of resources for the public health sector on climate change.