Fresh water, the stuff of life, is set to become even more precious as global warming begins to bite, experts warn ahead of World Water Day on Thursday. The theme of this year's event is water scarcity, a problem familiarly driven by population explosion, chronic wastage and pollution.

The UN estimates that, by 2025, two-thirds of the planet's population will be living with water stress, with North Africa, the Middle East and West Asia the worst-afflicted regions.

But global warming is bound to accentuate the scarcity, say experts.

In many regions, greater aridity, shifting rainfall patterns and dwindling runoff from snow and ice in mountains may badly deplete rivers, lakes and aquifers.

In contrast, other regions will get more rainfall — but this may take the form of fierce rainstorms that cause flash floods rather than a useful drizzle that soaks into the ground.

Or the precious stuff may fall in areas that are sparsely populated or where there is no infrastructure for capturing and storing it for use during dry spells.

Scientists in the UN's Intergovernmental Panel on Climate Change (IPCC) are due to highlight the phenomenon in a report, due to be released in Brussels on April 6. It is the second volume in a long-awaited assessment on global warming.

Water scarcity: A factfile

+ Water scarcity is defined as water availability of less than 1,000 cubic metres (35,000 cu. feet) per person per year. Many regions suffer chronic scarcity, defined as water availability of less than 500 cu. m. (17,500 cu. ft.) per person.

+ Water consumption rose sixfold in the 20th century, but per capita distribution today is plummeting. In 1950, consumption was 16,800 cubic metres (588,500 cu. feet) per person; in 2000, it was 7,300 cu. metres (255,500 cu. ft.) In 2025, when the world's population is expected to be eight billion, it will be 4,800 cu. metres (168,000 cu. ft.) per person.

+ Water consumption in residential areas varies from 10-20 litres (2.2-4.4 gallons) per person per day in sub-Sarahan Africa to 200 litres (66 gallons) in Europe and 350 litres (77 gallons) in North America and Japan.

+ Population growth, waste and industrial pollution are the biggest causes of water scarcity.

+ By 2025, two-thirds of the world's population will live in countries with serious water supply problems, especially North Africa, Middle East and West Asia.

+ Competition for water supplies has major potential for conflict as countries, or even regions within a country, squabble over extraction rights from rivers and lakes.

+ Climate change will add significantly to water stress, as it will change rainfall patterns and shrink snow and ice cover that feed rivers.

In higher latitudes and some wet tropics, including populous areas of East and Southeast Asia, water availability is "very likely" to increase over this century, according to the latest draft of the report, seen by AFP.

But countries in the mid-latitudes and dry tropics, which are already water-stressed, would have less water.

"Drought-affected areas will likely increase and extreme precipitation events, which are likely to increase in frequency and intensity, will augment flood risk," according to the document, which is still being finalised.

It adds: "Water volumes stored in glaciers and snow cover are very likely to to decline, reducing summer and autumn flows in regions where more than one-sixth of the world population currently live."

In global terms, a temperature rise of 2 C (3.8 F) by 2100 compared with 1990 levels — towards the lower end of the IPCC's estimates of the likely warming — would place up to two billion in a position of "increased water scarcity."

A rise of 4 C (7.2 F) would bring the tally to as many as 3.2 billion people, the draft calculates. Africa and Asia would be the two worst-affected continents.

But rich countries, which have more money, technical resources and expertise, also face the problems of water stress.

From the fast-growing "sun belt" states of the southwestern United States to southeastern Australia, where water is extracted from depleted rivers or ancient aquifers are run down for lawns, golf courses and swimming pools, climate change could also mean a wrenching change in lifestyle.

In February, the European Environment Agency urged European governments to start planning now to cope with climate-induced water stress, and singled out southern Spain, southern Italy, Greece and Turkey as being badly exposed.

Reservoirs and use of ground water stocks are designed for a relatively long "recharge" season of rain or runoff from melting snow.

If the recharge season is short, or it provides so much rain in one go that the ground surface saturates and the water infiltrates, the result is flooding and later scarcity.

earlier related report

World Water Assembly calls for right to water

by Amelie Bottollier-Depois

Brussels (AFP) March 21 – Participants in the World Water Assembly, gathered in Brussels this week, called for water to be recognised as a basic right and control over it to be kept out of the hands of private enterprise.

At a meeting just before World Water Day on Thursday, elected officials, members of civil society and non-governmental organisations underlined their concern that water was increasingly a source of strategic and economic conflict.

"Access to fresh drinking water for everyone, in all our countries, is a fundamental right. For us, water is life," said Bolivia's minister for water Abel Mamani.

"Establishing a right to water, therefore is another way of recognising the right to life already enshrined by the United Nations," he said. "Recognise water as a human right!"

The United Nations estimates that, by 2025, two-thirds of the planet's population will be living with water stress, with North Africa, the Middle East and West Asia the worst-afflicted regions.

Experts say global warming will take its toll on supplies.

In a message to the assembly, gathered at the European Parliament in Brussels, Italian Environment Minister Alfonso Pecoraro also underlined the need to recognise this "semi-precious" resource as a "public good".

Indeed the assembly set the international recognition of the unique status of water as its primary goal.

"Our target is December 10, 2008 — the 60th anniversary of the Universal Declaration of Human Rights — for the UN's human rights council to recognise water as a human right," said Riccardo Petrella from the World Water Contract.

He said that water "is essential for all forms of life" and called for public service providers to unite and bring an end to its "marketing".

"Public water suppliers account for 80 percent of world water supplies and they are letting the private sector, which controls 20 percent, call the shots," he told the assembly, which met over three days.

Christiane Franck, the head of Belgium's public water works Vivaqua, said "everything possible must be done to ensure that the issue of water is placed, or returned, into the hands of the public."

In fact, 90 percent of the world's waters are in public hands but the participants believed that this was not enough.

They also argued that the costs for providing water were not high enough to warrant investment from private enterprise.

The World Water Assembly estimated that "less than 50 billion euros (66 billion dollars) per year" to provide the vital quantity of 50 litres of water per day "to each of the 1.2 billion humans who do not have it."

It suggested that the money could be raised through new methods like taxes on airline tickets, park operators or on excess water consumption in richer countries where it is more plentiful.

The assembly now plans to set its demands in a letter to heads of state and government and the United Nations in an effort to convince them of the need to establish this new "human right".

Source: Agence France-Presse