Global climate change impacts in the United States: Adaptation

Adaptation measures improve our ability to cope with or avoid harmful climate impacts and take advantage of beneficial ones, now and as climate varies and changes. Adaptation and mitigation are necessary elements of an effective response to climate change. Adaptation options also have the potential to moderate harmful impacts of current and future climate variability and change. The Global Climate Change Impacts Report identifies examples of adaptation-related actions currently being pursued in various sectors and regions to address climate change, as well as other environmental problems that could be exacerbated by climate change such as urban air pollution and heat waves. Some adaptation options that are currently being pursued in various regions and sectors to deal with climate change and/or other environmental issues are identified in this report. A range of adaptation responses can be employed to reduce risks through redesign or relocation of infrastructure, sustainability of ecosystem services, increased redundancy of critical social services, and operational improvements. Adapting to climate change is an evolutionary process and requires both analytic and deliberative decision support.

Many of the climate change impacts described in the report have economic consequences. A significant part of these consequences flow through public and private insurance markets, which essentially aggregate and distribute society's risk. However, in most cases, there is currently insufficient robust information to evaluate the practicality, efficiency, effectiveness, costs, or benefits of adaptation measures, highlighting a need for research. Thus, the discussion of various public and private adaptation examples should not be viewed as an endorsement of any particular option, but rather as illustrative examples of approaches being tried. Adaptation planning efforts such as that being conducted in New York City and the Colorado River will be described.

Climate will be continually changing, moving at a relatively rapid rate, outside the range to which society has adapted in the past. The precise amounts and timing of these changes will not be known with certainty. The United States has considerable capacity to adapt to climate change, but during recent extreme weather and climate events, actual practices have not always protected people and property. Vulnerability to extreme events is highly variable, with disadvantaged groups and communities (such as the poor, infirm, and elderly) experiencing considerable damage and disruption to their lives. Adaptation tends to be reactive, unevenly distributed, and focused on coping rather than preventing problems. While it is difficult to fully evaluate the impacts of climate change on the United States without considering the consequences of climate change elsewhere, such analysis is beyond the scope of this report. The report identifies a number of areas in which inadequate information or understanding hampers our ability to estimate future climate change and its impacts. Reduction in vulnerability will require anticipatory deliberative processes focused on incorporating adaptation into long-term municipal and public service planning, including energy, water, and health services, in the face of changing climate-related risks combined with ongoing changes in population, land use and development patterns.