How to Reduce Our Water Footprint to a Sustainable Level?

• Author: Hoekstra, Arjen Y.

Freshwater scarcity is increasingly perceived as a global systemic risk. In its last seven annual risk reports, since 2012, the World Economic Forum lists water crises as one of the top five risks to the global economy in terms of potential impact. (1) A recent study shows that two thirds of the global population live under conditions of severe water scarcity for at least one month of the year. (2) Nearly half of those people live in China and India. Half a billion people in the world face severe water scarcity all year round.

Overconsumption of water is widespread. Rivers such as the Yellow River in China and the Colorado River in the United States do not even meet the ocean anymore. Along their way, the water from these rivers is withdrawn to supply farmers, industries and households. The Aral Sea in Central Asia and Lake Urmia in Iran have nearly disappeared as a result of upstream water use. Groundwater reserves are being depleted at worrying rates as well, on all continents. The United States, for example, is overexploiting its High Plains and Central Valley Aquifers, India and Pakistan their Upper Ganges and Lower Indus Aquifers, and China its Northern China Aquifer. Abstraction rates of 10 to 50 times natural recharge rates are quite common. (3) In many places, such as Yemen, groundwater tables fall by one metre per year. Water pollution is pervasive as well. Fertilizers and pesticides from farming end up in rivers, violating water quality standards without any serious action taken by authorities. Several streams in Bangladesh and China appear red, purple or blue due to wastewater from the apparel industry, with colours depending on the latest fashion in the West.

Some of us, like myself, live in rainy areas where water scarcity seems like a remote problem, but we can still relate to it. A surprising 40 per cent of the water footprint for European consumers lies outside the continent, often in places facing severe water problems. Much of our food and many other goods are imported from countries with water-stressed catchments. Food production, in particular, uses a lot of water. To produce one 200-gram steak, an average of 3,000 litres of water is consumed. A 200-gram chocolate bar requires 3,400 litres of water. Feed for livestock and food for our direct consumption are intensively traded, often coming from water-scarce places. For example, it has been estimated that about 50 per cent of the water footprint of consumers in the United...