countries in international climate change agreements; the development of global agreements for reducing emissions of species such as methane, tropospheric ozone precursors, black carbon, and HFCs; and the efforts to retire existing carbon-intensive infrastructure (in particular, poorly controlled power plants located in densely populated areas).

When considered in a long-term global context, climate change presents an array of challenging ethical dilemmas; for example, debates about how to fairly allocate responsibilities for reducing GHG emissions among low- and high-income countries have stymied international negotiations for years. Likewise, many argue that climate change is, at its core, a question of intergenerational equity: To what degree should current generations take action to protect future generations from harm?

While these are tremendously important issues to grapple with, this section focuses more narrowly on a set of concerns of particular interest to U.S. policy makers—how policies for reducing domestic GHG emissions may alleviate or exacerbate equity and “environmental justice” among different parts of American society. We examine how such policies will cause different impacts across regions and population groups due to variations in the nature and carbon intensity of regional economic activity, and in the resources and adaptability of different populations. We then focus on examining how policies to limit climate change may affect economic and employment opportunities across the country, since employment opportunities are of course a key means of enhancing equity.

Climate change impacts, and actions to limit these impacts in the future, will take place in the context of existing social and economic disparities, many of which are related to environmental concerns. In the United States, households in inner cities and rural areas, and African- and Hispanic-American households, are disproportionately poor. In metropolitan areas, poor households locate where housing costs are lowest, often in zones of heavy industry or near noxious facilities (e.g., waste treatment plants, transportation facilities, and power plants); as a result, exposure to air pollution and toxics is greater among low-income and minority households (Brulle and Pellow, 2006; Schweitzer and Stephenson, 2007). Poor households in rural areas suffer severe mobil-