Growing freshwater scarcity owing to rising water demands and a changing climate is increasingly perceived as a major risk for the global economy. In a special issue of Nature Climate Change, devoted to this emerging global concern, professor Arjen Hoekstra from the University of Twente argues that consumer awareness, private sector initiatives, governmental regulation and targeted investments are urgently necessary to move towards sustainable water use across value chains.
With an editorial and a series of commentary pieces, Nature Climate Change puts the concern over increasing freshwater scarcity and the key role of business firmly on the international political agenda. The unsustainable management of water resources, together with rising water demands and the impacts of climate change, poses significant risks to water companies and businesses reliant on agriculture. Companies become increasingly aware of water risks in their operations and supply chain. Andy Wales, Head of Sustainable Development for SABMiller, said: "For us at SABMiller, water is vital not only in the brewing process but also to grow the crops used to make beer and to generate electricity to power our breweries. We must therefore simultaneously tackle direct water usage in our operations as well as the water needs of agricultural and energy systems."
Good water stewardship includes the evaluation of the sustainability of water use across the entire value chain, the formulation of water consumption and pollution reduction targets for both the company's operations and supply chain, the implementation of a plan to achieve these targets and proper reporting on all this.
In his commentary, professor Arjen Hoekstra of the Twente Water Centre argues that the private sector's commitment alone will not be enough to achieve the management shift required to sustainably meet the needs of millions of water consumers around the world and calls for a strengthening of the role of governments to implement new regulation of water use. He says: "Despite good efforts undertaken by several companies, it is unlikely that the business sector as a whole will sufficiently regulate itself. There is an urgent need for governmental regulation and international cooperation. Governments should develop monthly water footprint caps for all river basins in the world to ensure sustainable water use within each basin". A water footprint cap sets a maximum to the water consumption and pollution in a river basin, to avoid that water use in a basin exceeds the basin's carrying capacity.
And more is needed than agreeing on a maximum water footprint per river basin. When allocating certain water footprint permits to specific users, governments should take into account what is reasonable water use. Governments and business should join in an effort to establish water footprint benchmarks for water-intensive products such as food and beverages, cotton, flowers and biofuels. The benchmark for a product will depend on the maximum reasonable water consumption in each step of the product's supply chain, based on best available technology and practice.
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