Given the coming impacts of climate change described in the recent IPCC report, it is time to start thinking rationally about settlement abandonment. Low-lying coastal areas and small islands are at long-term risk from sea level rise, but settlements in semi-arid regions, at high latitudes, and in areas exposed to extreme weather events will experience severe impacts sooner. Many settlements are poorly prepared, and some may become uninhabitable.
In a world of 7 billion people, habitable space is scarce. Locations with the reliable freshwater supplies, fertile soils, and energy sources needed to support dense populations are limited. Technological innovations like agriculture, fossil fuels, irrigation, and air conditioning expanded the human habitat; but unless some as-yet unrealized technological revolution of similar magnitude emerges, the spatial extent of our habitat has reached its maximum. It will now shrink because of climate change.
Historically, settlement abandonments have been rare. Most resulted from sudden political, economic, or technological changes; from armed conflicts; and from construction of large dams.[i] Environmentally linked abandonments have been less common, and fall into two categories:
- events where human activities profoundly altered the natural environment (e.g. nuclear accidents)
- extreme, naturally occurring events like droughts, floods, and volcanoes, that overwhelmed unprepared settlements
What should the World Bank do when asked to support investments in places that might one day need to be abandoned? First, identify and address any non-environmental factors that increase the risk of settlement abandonment, because they unfold much faster than do the impacts of climate change. Detroit lost a half-million people in fifty years as its auto industry contracted. Aral Sea fishing settlements were abandoned because of poor Soviet planning. Dam construction in Asia has displaced tens of millions of people since 1950. Economic and political forces like these are more immediate threats to human settlements than is climate change
Second, invest in physical and social infrastructure that give people living in at-risk settlements more adaptation choices, ones that minimize potential climate-related losses, increase sustainability, and respect people’s entitlements and rights to a decent livelihood. Worst-case abandonment scenarios occur when people are forced into refugee-like distress migration, potentially leading them to situations of greater risk. These must be avoided. If a settlement must eventually be abandoned, it should be a process whereby residents migrate freely, with choice and dignity, having first realized their full human potential.
In developed countries this means channeling incentives for proactive adaptation through public and private institutions. In less-developed nations with weak institutional safety nets, the goal must be to build institutional capacity while simultaneously helping communities and households diversify their livelihood opportunities. People who have freedom to make suitable livelihood choices, to be mobile, and to chart their own futures are more resilient and adaptable to environmental stress. Building adaptive capacity today is the best preparation for settlement abandonments in the future.