This session brings together eminent scientists and pressure groups from New York to New Delhi to examine available options that can allow society to deal with the urgent task of mitigating climate change, while continuing to improve living conditions. Speakers will evidence that although reductions in carbon dioxide emissions and other long-lived greenhouse gases are essential for mitigation of long-term climate change, real leverage over near-term climate comes primarily from the tropospheric ozone precursors methane, carbon monoxide, and volatile organic compounds and, at least regionally, from black carbon aerosols. Case studies will show how these short-lived pollutants contribute to both global warming and many of the most alarming regional climatic changes, including the melting of Himalayan glaciers and Arctic sea ice and shifts in regional precipitation. They also contribute to air pollution, with adverse effects on human health, agricultural yields, and other social-economic costs. Speakers will argue for a new and more integrated approach, in which emission reductions in specific sectors are optimized to get benefits for air quality and climate. Presentations will show how this can be more robust and more cost-effective than policies that aim at air quality and climate targets separately. This session will report on recent studies in support of an assessment by the United Nations Environment Program (UNEP) of the above-mentioned options.