A report released Wednesday, June 10, draws frightening pictures of what global warming could mean for hundreds of millions of people who might find themselves with too little water, too much, or the wrong kind. As glaciers continue to melt in the Himalayas flood risks will increase down-river, while in the longer run decreased flows will threaten agricultural production in some of the world’s most densely populated regions. At the same time, "sea level rise will worsen saline intrusions, inundation, storm surges, erosion an other coastal hazards." Such developments already are visible around the world and could, by mid-century, displace people on a scope and scale that would "vastly exceed anything that has occurred before."
That is the central conclusion of In Search of Shelter: Mapping the Effects of Climate Change on Human Migration, a collaborative study in which the relief organization Care International played a leading role. Two years ago, Christian Aid issued a report on the same subject in which it predicted that 1 billion people might be displaced by climate change by 2050.
The Care report was written with scholars from the United Nations University and Columbia University, and drew on field resources deployed for an ongoing European study of forced migration, EACH-FOR. Climate mapping was done by researchers at Columbia’s Center for International Earth Science Network.
"Climate change is happening with greater speed and intensity than initially predicted," says the report, explaining its rationale. "Therefore, the challenges and complex politics of adaptation are joining those of mitigation at the center of policy debates."
Detailing the kinds of conditions that are almost sure to get worse, the report notes that more than 300 million Africans already are suffering from water scarcity, with ares affected by water shortages "likely to increase by almost a third by 2050." An area of central Mexico singled out by the CIESIN map-makers could see water runoff decline by 25 to 50 percent. The most drastic changes are expected, however, in the highly populated areas of southern and eastern Asia that depend on runoff from the Himalayas to nourish agriculture.
The disappearance of glaciers in what's known as the Water Tower of Asia "implies decreased water supply and untimely flows--that is, [flows] coming in the wrong (non-cropping) season." Increasingly parched conditions in the Indus, Ganges, Mekong, Yangtze, and Yellow River valleys (among others) could drive inland-living people toward the coasts, where some could end up vulnerable to the effects of sea level rise instead. The Mekong Delta, for one, is home to 18 million people and produces half of Vietnam's rice, 60 percent of its shrimp harvest, and 80 percent of its fruit. Similar patterns are found in the Ganges delta, China's two major deltas, and, for that matter, the Nile’s.
The Care-Climate report shies away from making numerical predictions, though it cites estimates that the number of people displaced by climate change could go as high as 700 million by mid-century. It emphasizes that the effects of climate change are not easily disentangled from numerous other environmental and demographic factors. Its recommendations are not always compelling and sometimes are framed in language that seems irrelevantly "correct." But the report does make vividly clear that climate change is not just a matter of rich countries' taking action to reduce their emissions so as to cut risks to themselves. Global warming already is affecting millions of people living in straitened circumstances, and it will continue to do so, requiring concerted attention and action.