This report describes efforts by the ClimateWorks Foundation and the World Bank to quantify the multiple economic, social, and environmental benefits associated with policies and projects to reduce emissions in select sectors and regions. The report has three objectives: 1) to develop a holistic, adaptable framework to capture and measure the multiple benefits of reducing emissions of several pollutants; 2) to demonstrate how local and national policymakers, members of the international development community, and others can use this framework to design and analyze policies and projects; and 3) to contribute a compelling rationale for effectively combining climate action with sustainable development and green growth worldwide. By using a systems approach to analyze policies and projects, this work illustrates ways to capitalize on synergies between efforts to reduce emissions and spur development, minimize costs, and maximize societal benefits. This report uses several case studies to demonstrate how to apply the analytical framework. Three simulated case studies analyzed the effects of key sector policies to determine the benefits realized in the United States, China, the European Union, India, Mexico, and Brazil. The sector policies include regulations, taxes, and incentives to stimulate a shift to clean transport, improved industrial energy efficiency, and more energy efficient buildings and appliances. Also presented are results of four simulated case studies that analyzed several sub-national development projects, scaled up to the national level, to determine the additional benefits over the life of each project, generally 20 years. By applying the framework to analyze both types of interventions, this report demonstrates the efficacy of this approach for national and local policymakers, international finance organizations, and others. These case studies show that climate change mitigation and air quality protection can be integral to effective development efforts and can provide a net economic benefit. Quantifying the benefits of climate action can facilitate support from constituencies interested in public health and food and energy security; it can also advance the international discussion of effective ways to address climate change while pursuing green growth.