Small Islands to Face a Freshwater Scarcity
Island populations are likely to face much greater scarcity of freshwater in the coming decades than previously thought, according to new research.
Current global climate models (GCMs) indicate that 50 percent of small islands will become wetter, and 50 percent drier, by the middle of the century, but this new study, published Monday in Nature Climate Change, contends that a more accurate estimate puts 73 percent at risk of increased aridity.
The basis of this substantial discrepancy is that current GCMs tend to have a resolution that is too coarse to consider any islands much smaller than New Zealand's, which means that while they are able to account for rainfall, the effects of evaporation from land remain ignored for small islands.
“The basic issue underlying this is that people need water,” says lead author Kris Karnauskas of the University of Colorado, Boulder, in a telephone interview with The Christian Science Monitor. “It’s fairly fundamental, whether you’re living in the middle of continental USA or Australia, or out in the open ocean.”
What he found, however, was that in many Intergovernmental Panel on Climate Change (IPCC) reports, there were plenty of “beautiful maps” that considered the aggregated amount of water, but “out there in the ocean,” there simply was no data.