Adapting to Climate Change: Assessing the World Bank Group ...

CHAPTER 1CONTEXT AND APPROACHOften this occurs as once-extreme events happen more and more frequently. Forinstance, as the sea level rises, devastating but once-rare storm surges may occurmore and more often until a low-lying atoll becomes uninhabitable. Some examplesof transformational change include:Freshwater supplies that are becoming salinized in coastal regions and onlow-lying islands.Climatic zones that are shifting uphill and toward the poles, displacing thetraditional belts of grain, coffee, and other crops. Already, the trend increasein temperature in many grain-growing areas is large compared to year-toyearvariability 1 . This is estimated to have depressed maize production in2008 by 3.8 percent and wheat production by 5.5 percent compared to ahypothetical world in which climate patterns remained as they were in 1980(Lobell, Schlenker and Costa-Roberts 2011). Farmers will not be able to keepgrowing current crop varieties in current locations for long.Biodiversity-rich ecosystems that will suffer as temperatures rise andmigrating species find “escape routes” blocked.The disappearance of glaciers and mountain snowpacks that will result inwinter floods and summer droughts in the watersheds below.1.5 Some climate change trends can more easily be projected than others. Ingeneral, trends are more easily detectable and predictable for temperature than forprecipitation, for large areas rather than small, and for means rather than extremes.In some cases the risks cannot be reckoned, but this is no cause for complacency. Forinstance, precipitation projections for West Africa vary tremendously. By the end ofthe century, the areas suitable for millet-growing under the wettest projections arecompletely different from the suitable areas under the driest projections(Washington and Hawcroft 2012). So West African countries need to be preparedfor a wide range of possible futures.1.6 The scale of the adaptation challenge depends on how vigorously globalgreenhouse emissions are curbed. While the global community has committed to agoal of restricting average global temperature rise to 2° C, that goal is nowconsidered nearly unattainable (IEA 2011). Life in a world 4° C hotter will be costlierand beset with more uncertainties. The less the climate is stabilized, the greater theneed to plan for the possibility of transformational change at the regional and globallevel.3