The world’s fresh water supplies are almost fully exploited.Almost al, 97 per cent, of the world’s water is salt. Of the fresh water in the world, two thirds is locked up as ice and snow (the cryosphere – to you and me, kid!). Globally, three quarters of the water that is used is used by agriculture. India, China and the United States, use more fresh water than is available. The water level in those nation’s aquifers is falling as a result.The current food crisis has come about largely as a result as the shortfall in available water begins to impact on the cost of irrigation.Â
Stemming the water wars Water shortages will not go away by themselves. They are a global problem and demand a global reponse Jeffrey Sachs guardian.co.uk, Sunday 26 April 2009 17.00 BST Article history Many conflicts are caused or inflamed by water scarcity. The conflicts from Chad to Darfur, Sudan, to the Ogaden Desert in Ethiopia, Continue Reading →
This map shows the change in run-off inferred from streamflow records worldwide between 1948 and 2004, with bluish colors indicating more streamflow and reddish colors less. Graphic: Journal of Climate, modified by UCAR
The most population regions of the world coincide with major rivers, many of which will be seriously depleted due to global warming. The double impact of increased population and water use, along with higher temperatures and lower rainfall is expected to bring acute water shortages to China, India and much of Africa. A report released last week by the Center for Atmospheric Research in Colorado shows that only the Missisippi and the Nile have gained increased run-off as a result of climate change in the last fifty years.
Forests might pump water from the ocean to the inland of major continents, Russian scientists told New Scientist last week. The transpiration of moisture from forests leads directly to lower air pressure as that moisture condenses, creating winds that suck in further moisture from the ocean, the scientists say. The theory was first published in 2007 but has received little support until last week. A UK scientist, Doug Shiel, working in Uganda has revealed that traditional hydrology models cannot account for the increased rainfall over forests compared to neighbouring lands at the same latitude with similar geography. Shiel says the “biotic pump” that forests provide could account for the high inland rainfall of the Amazon and Congo rainforests, compared to areas like the Sahara and Australian deserts.
Adelaide University’s Professor Mike Young’s appeal to “downsize” the river system included the possible abandonment of some of Victoria’s prized river red gums in the Barmah forest.
The Australian Minister for Water and Climate Change, Penny Wong, said last week that the federal government’s $24 million purchase of Toorale station near Bourke in western NSW had resulted in 11billion litres of water flowing down the Darling that would not have been available otherwise. Landowners along the Warrego River which flows through Toorale Station and into the Darling have activated sleeper licenses which allow them to pull out more water when it is available. Wong said she is aware of the issues raised by these entitlements but that is beyond the scope of the existing buy back scheme.
A combination of government buy-back and thirsty irrigators has earned agribusiness giant, Tandou more than 43 million dollars in the last 12 months. The company sold one quarter of a million megalitres to the government late last year, announcing that the sale was sufficient to pay off all the company’s bank debt. It has continued to sell temporary water allocations and is now cashed up and looking for opportunities to buy up land and water rights from distressed farmers. The company retains rights to over 30,000 Megalitres of water.