There's bad news from the largest ever assessment of global freshwater resources. The report suggests that many more people are struggling for water, either because there is not enough fresh water in the area or there is no infrastructure to provide access. The report, released at a water conference in Sweden on 20 August, calls for an immediate overhaul of water management policies.
With supplies of fresh water diminishing and populations increasing, water scarcity is set to become a major problem for the 21st century. But when will the world start feeling the pinch? The consensus, based on population and water demand trends, has been that about one third of the world's population will be hit with extra illness and poverty due to water scarcity in 2025. But without a comprehensive analysis of all the factors that affect freshwater sources--agricultural practices, in particular--this is a very rough estimate.
The worrisome predictions for 2025 motivated 700 water experts around the world to collaborate on a 5-year study of global water resources to get a better fix on the problem. The effort was orchestrated by the International Water Management Institute (IWMI) in Colombo, Sri Lanka, and funded by the United Nations and several charitable foundations. The researchers compared water management policies and outcomes on every continent over the past 50 years, and they updated data on the current state of freshwater resources.
The results suggest that the situation is far more urgent than has been thought--one third of the world's population is already affected by water scarcity--and the future more grim. The authors call for immediate change in water policies, singling out more efficient irrigation and wastewater reuse as the top priorities. However, there will be tough choices even with the best water management policies, says David Molden, a hydrologist at IWMI who led the study. "It is possible to reduce water scarcity, feed people, and address poverty, but the key trade-off is with the environment." For example, more dams can provide better control of freshwater resources, but they also destroy ecosystems downstream.
The breadth and depth of the report are impressive, says David Brooks, an environmental scientist at Friends of the Earth in Ottawa, Canada, who has read a draft. Brooks says the new report "goes beyond food production to identify links to human health and to rural poverty," whereas previous efforts have had a "rather narrow emphasis on agricultural technology and production efficiency."