West, have begun planning to address adaptation beyond infrastructure per se, including more efficient water markets. Although noninfrastructural strategies, such as improving emergency preparedness and response (above), have also been considered, in general there is insufficient concern with, or scientific understanding of, the underlying social-ecological vulnerabilities that cities and the people within them face (see Chapter 4). Many more ways to reduce vulnerability and enhance adaptive capacity may become available when the vulnerabilities of cities are better understood, particularly the vulnerability of subpopulations (e.g., the urban poor, minority groups, children, the elderly, or manual laborers; Campbell-Lendrum and Corvalán, 2007) and the differences between large and smaller urban areas in different regions (e.g., Bartlett, 2008; Hardoy and Pandiella, 2009; Hess et al., 2008; Porfiriev, 2009; Thomalla et al., 2006). Urban areas adjacent to ecological reserves or bordering on forested areas or wildlands may also have to take preventive and preparatory measures to reduce wildfire risks and find ways to protect urban ecology (Collins, 2005).
In general, urban areas face all the climate-related problems faced in other sectors described in this report, but focused on a particular spatial scale. While lessons and techniques on adaptation to climate change from one urban area may be transferrable to others, many will be location specific, and clusters of municipalities in close proximity will have to devise integrated responses across extended metropolitan areas. These considerations raise both institutional and economic opportunities and challenges for adaptation (see the companion report Adapting to the Impacts of Climate Change [NRC, 2010a]). They also open up the opportunity to develop sustainable solutions to climate change that integrate actions to limit the magnitude of climate change with those taken to adapt to its impacts—a challenge that some cities around the world are already exploring (e.g., Heinz Center, 2008b). Important scientific questions remain, however, about how to analyze these dual strategies in an integrated fashion (e.g., Hamin and Gurran, 2009; Wilbanks, 2005).
Because the majority of the U.S. and world population already lives in urban areas, and existing or new urban centers will continue to grow in size and economic importance, research on reducing the climate change and accompanying environmental impacts of urban areas is critical. This includes assessing the differential vulnerability of urban areas and populations to climate change impacts as well as the full range of options for limiting and adapting to climate change. Opportunities for integrated, multidisciplinary, and use-inspired research abound, but better connections are needed particularly to the applied science, engineering, and planning professions.