The Integrated Assessment of Black Carbon and Tropospheric Ozone establishes the climate cobenefits of air-quality measures that address black carbon and tropospheric ozone and their precursors. The measures identified to address these shortlived climate forcers have been successfully tried around the world and have been shown to deliver significant and immediate development and environmental benefits in the local areas and regions where they are implemented. Costs and benefits are region specific, and implementation often faces financial, regulatory and institutional barriers. However, widespread implementation of the identified measures can be effectively leveraged by recognizing that near-term strategies can slow the rate of global and regional warming, improving our chances of keeping global temperature increase below bounds that significantly lower the probability of major disruptive climate events. Such leverage should spur multilateral initiatives that focus on local priorities and contribute to the global common good. February 2011