Gauteng and NW Province

Act now to avert a global water crisis

24 May 2013 by Charles Vörösmarty and Claudia Pahl-Wostl

We desperately need joined-up thinking by the world’s leaders to secure future water supplies, say Charles Vörösmarty and Claudia Pahl-Wostl

Earth is often described as the blue planet, suggesting that there is plenty of water. And indeed there is. Hardly any of it, though, is available for people to use.

Fresh water is only 2.5 per cent of the total, and 70 per cent of that is locked up in ice and snow. Water in rivers and lakes makes up less than 0.3 per cent of the world’s fresh water. Globally, fresh water is scarce, and getting scarcer.

That is why the Global Water System Project gathered more than 350 water scientists in Bonn, Germany, this week to discuss this crisis. The conference title – Water in the Anthropocene – recognises that human behaviour is the major factor shaping changes to global water cycles. Countless millions of individual local human actions add up to regional, continental and global changes that have drastically shifted water flows and storage, impaired water quality and damaged aquatic ecosystems.

We have altered the planet’s climate and chemistry, its snow cover, permafrost, sea and glacial ice extent, and ocean volume: all fundamental elements of the hydrological cycle.

We have accelerated major processes like erosion, applied massive quantities of nitrogen that leaks from soil into ground and surface waters and, sometimes, literally siphoned all water from rivers, emptying them for human uses before they reach the ocean. We have diverted vast amounts of fresh water to harness fossil energy, dammed major waterways and destroyed aquatic ecosystems.

These changes put us on an unsustainable trajectory – that much we know. However, current scientific knowledge cannot predict exactly how or precisely when we will breach a planetary-scale boundary, a tipping point that could trigger irreversible change with catastrophic consequences.

In an attempt to forestall such a catastrophe and move toward a more sustainable path, the conference has issued a declaration, adopted by the 350 scientists who attended and likely to be backed by many more, that sets out some of the problems and how to address them.

Those problems are not restricted to developing nations. Maps of water availability per person, for example, show hotspots of scarcity across much of Europe and North America. That may come as a surprise to everyone else staying in the conference hotel, whose showers and taps deliver water at any time of the day or night.

The assembled water scientists, though, learned that such abundance in the major economies of the world was bought at a cost of an annual $750 billion investment in infrastructure. Is that kind of money going to be available to bring water to the poorer people of the world?

Costly hard engineering solutions such as large reservoirs and water transfers from one basin to another deliver water in rich countries. Will the best solution be to rely on these approaches exclusively, whether in the rich world or in developing nations?

The engineering solutions being designed and built now have long lives ahead of them. Changing conditions around the world may render them useless, and as an alternative many of the scientists in Bonn urged a fresh consideration of the services that healthy ecosystems can give us, among them flood protection and pollution abatement.

Famously, New York City found it cheaper to pay farmers in the Catskill mountains to change their farming practices than to invest in new water-treatment plants. This approach could and should be investigated in many more places.

In addition, aquatic ecosystems are in peril. Of all known species, 7 to 12 per cent are heavily dependent on fresh water, and around 30 per cent of them are endangered, a far higher proportion than for other habitats.

One of the great problems we face in helping the powers that be to make sensible decisions is that despite all the research we often lack the most basic information. The number of monitoring stations to measure water flows and quality has collapsed, and some countries that share water resources with others nevertheless jealously guard the data they do have, making it even harder to manage international river basins.

We urgently need a new, globally integrated monitoring system, using on-the-ground and satellite technologies, and feeding standardised databases that all can use. Citizen scientists, equipped with basic training and mobile phones, could well play an important role in better water monitoring.

Above all, perhaps, we need a change in the way water is governed. Institutions have lagged behind technology and changing circumstances. In the Aral Sea, for example, hydropower and agriculture make competing claims on water, despite research that demonstrates how both can be optimised effectively.

Indeed, perhaps the most important conclusion of the conference is that water needs to be considered not in isolation but as part of a water-energy-food nexus, in which each sector affects, and is affected by, the others.

At the centre of that nexus is human well-being, and as the world moves towards setting new goals for sustainable development, we urge that fresh water be integrated into all of them. It is no good calling for food security or better health, for example, without realising that both depend on water security.

In just one or two generations from now, most of the 9 billion people that will occupy this blue planet will be living under the handicap of severe pressure on fresh water. This handicap will be self-inflicted and is, we believe, entirely avoidable.
Claudia Pahl-Wostl is director of the Institute of Environmental Systems Research in Osnabrück, Germany. Charles Vörösmarty is chairman of the US National Research Council’s committee on hydrologic sciences. They are co-chairs of the Global Water Systems Project

I see it daily with our water conservation systems installations; it is the middle to upper class that can afford it. It is not the poor of the poor. The poor of the poor will buy a tank or even worse depend on a water tank as a donation. The middle class will install the water tank and harvest their own rainwater. The upper class will harvest the rainwtaer and have it purified for drinking purposes.

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