Short-term exploitation of African land and water may lead to long-term problems

New Scientist : Countries such as China, India, and Saudi Arabia have begun to lease well-watered land in Africa to grow food crops. Doing so is cheaper and easier than maintaining and improving the water resources back home, writes Anil Ananthaswamy for New Scientist. To study this global virtual water trade network, researchers Ignacio Rodriguez-Iturbe of Princeton University and Samir Suweis of the Swiss Federal Institute of Technology in Lausanne have built a mathematical model—the first of its kind. According to their findings , published in Geophysical Research Letters, a small number of countries have a large number of connections to other countries to access their water resources, whereas a much larger number of countries have very few connections, rendering them more vulnerable to market forces. Thus, the richer countries tend to monopolize the world’s water supply. In another study published in Geophysical Research Letters, Paolo D’Odorico of the University of Virginia at Charlottesville and coworkers found that while, in the short term, a rise in the virtual water trade can prevent famine, in the long term such trade reduces societies’ resilience to catastrophes like exceptional droughts and crop failure, which could be on the rise due to climate change.