Social and Economic Impacts of Climate Change

Current Knowledge About Social and economic impacts

Some impacts of climate change are already being observed, mainly in the polar areas, where traditional societies are finding it difficult to sustain their ways of life and modern societies are facing the impacts of a thawing tundra on physical infrastructures. But in most cases, the recent major climate events in the United States—such as Hurricane Katrina in 2005 and Hurricane Ike in 2008, along with a summer heat wave in 2006 and regional water shortages in the winter of 2007–2008—cannot be attributed to climate change because climate has historically been so variable. These events can be considered examples of the impacts that could become more frequent with climate change, which is very instructive; but they cannot be interpreted with a high degree of confidence as impacts of climate change itself.

The more serious issues lie ahead. What might climate change mean for economies and societies in the long run? Climate change is expected to mean increases in average temperatures, more severe toward the poles; changes in both the total amount and the intensity of regional precipitation; changes in the intensities and locations of severe weather events; and sea-level rise. Clearly, such changes could be important in many locations, but projecting the impacts on human systems in the long term is complicated since other things will also be changing over that period, such as demographic patterns, global economic relationships, available technologies, and institutional structures and practices. The socioeconomic effects of climate change will depend on how climate change interacts with these other kinds of change. Consider, for example, how much climate change might increase by 2080 the vulnerabilities of people living in coastal areas subject to sea-level rise and seasonal storms. By that time, populations in vulnerable areas will have had three generations of experience with storms and coping strategies, from risks of storm disruptions and damages to increased costs and reduced coverage of losses from private insurance. Voluntary retreats from vulnerable coastal areas may have reduced potential damages considerably.

For this reason, assessments of socioeconomic impacts of climate change generally focus not on projections of long-term impacts, based on quantitative scenarios of direct climate change over periods of a century or more, but on climate change risks and vulnerabilities. In other words, rather than assuming a particular level of climate change in the far future, without equivalent assumptions about changes in socioeconomic contexts, analysts look at the sensitivities of human systems to climate variables: For example, based on experience with climate variability and other known factors, what difference would a change in average temperature or precipitation make, for instance, for energy requirements, for snowfall on ski resorts, or for disease vectors affecting human health? What is the range of effects of different magnitudes and rates of such a change in climate? In many cases, quantitative analysis is used not to produce hard numerical answers but to inform robust qualitative judgments about the large versus small, the urgent versus cautionary, the known versus unknown, and other guidelines for both decision making and further research.

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