Stigende mangel på ferskvand vil ramme både storbyer og verdens livsvigtige landbrug, men er vi forberedt på det? Forskere giver deres vurdering og peger især på det voksende vandforbrug i Asien – klodens tættest befolkede verdensdel.
LONDON, 1 August 2012 (IRIN): Is the world ready to face water shocks? For water shocks are certainly coming; water shocks, in fact, are already here.
A meeting of ecologists, policymakers and water professionals gathered recently at London’s Chatham House to contemplate (granske) the prospect. Asia, they heard, was the continent where problems were already most acute.
Pavel Kabat of Vienna’s Institute for Applied Systems Analysis told IRIN:
“We have been worried about water in other parts of the world – it is still a very important issue in Africa – but we were forgetting that the because of the economic growth and the population growth, the surge in food demand will come in Asia”.
“Already now the fresh water for agriculture is being consumed at very high rates. Asia is the hotspot… and I would say that the first big issues will have to be faced by 2020 or 2030.”
Seventy percent of the global use of water is for agricultural purposes, and that is where the crisis is likely to show itself.
“In India, 75 percent of all irrigation water comes from groundwater, and we are kind of assuming that it will stay like this”, says Kabat.
But he points to Europe and the USA, which have seen groundwater levels in some areas dropping by as much as five metres a year, and laws have had to be introduced to restrict the lifting of groundwater for agriculture; the same thing, he says could happen in Asia.
There is also the issue of water quality
With reduced flows of fresh water from Asia’s great rivers reaching the coast, and with sea levels rising, the Brahmaputra, Ganges and Mekong deltas are suffering increasing salt water intrusion, with salinity (saltholdighed) in some places reaching levels at which normal crops will not grow. Some coastal areas of Bangladesh are already unfarmable.
Developed countries are certainly not immune from the impending problems. In some areas of the USA ancient aquifers (underjordiske vandlag) have been tapped to allow agriculture in naturally desert areas.
This “fossil water” is now depleting fast and not able to be replenished (erstattet).
One speaker told the meeting he could see areas where there would soon be no more groundwater, which means no more agriculture, and, since people only settled there because they could grow irrigated crops, no more viability as a populated area – a prospect so alarming that, he said, “it causes policymakers not to want to tackle that problem.”
A threatened mega-city
Across the border in Mexico, it is the capital city which is threatened by an unsustainable situation. Already Mexico City has a serious water deficit and is facing a drop in rainfall of something like 30 percent.
The situation has been made worse by the fact that Mexico subsidizes public services in the capital; water is cheaper there than in the countryside, and the population is growing very fast. And once consumers are used to subsidies it becomes very hard to introduce a realistic price.
Polioptro Martinez Austria, director of the Mexican Institute of Hydrology, says water managers cannot solve this problem on their own.
“Today there are huge subsidies for water in the area,” he told IRIN, adding:
“As a result, the aquifers are overexploited, and the public awareness of water use is not enough to save water. I believe we need a new policy of urban development if we are going to solve the water problem.”
In India and Bangladesh, the arid areas of the USA and Mexico City, the impression is of a dreadful inevitability, like a slow-motion car crash. And politicians are not good at dealing with this kind of slow onset event.
“We know it has to come, but there is a general lack of ability of governments globally to look beyond the next election period”, says Kabat, noting:
“I am sorry to say. We have a lot of studies, as scientists, of the scenarios for the next 10, 20, 30 years, but it is simply too far ahead for politicians to act.”
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http://www.irinnews.org/Report/95990/WATER-Prepare-to-face-shocks
