Depletion of water resources more serious than oil reserves
The depletion of underground water resources through overpumping is a far more serious issue than the depletion of oil reserves, the head of an environmental think-tank has warned.Lester Brown, president and founder of the Earth Policy Institute, a Washington based independent research organisation, argues that: "There are substitutes for oil but there are no substitutes for water. Excessive pumping for irrigation to satisfy food needs today almost guarantees a decline in food production tomorrow."
The points are made in Brown's new book, Outgrowing the Earth: The Food Security Challenge in an age of falling water tables and rising temperatures. He says that two of the trends caused by excessive demand on the world's resources - falling water tables and rising temperatures - are making it more difficult for the world's farmers to adequately feed the 76 million people added to our numbers each year.
The food we consume requires 500 times as much water as we need to drink every day and agriculture is the most water-intensive sector of the economy. Seventy per cent of all water pumped from underground or diverted from rivers is used for irrigation, 20% is used by industry and 10% goes to domestic residences.
Water tables are falling in countries that contain over half the worlds people and Brown points out that, while numerous analysts and policymakers are concerned about a future of water shortages, few have connected the dots to see that a future of water shortages also means a future of food shortages.
The rising temperatures have also compounded the problem and altered the precipitation mix, meaning there is more flooding during the rainy season and less snowmelt from high altitudes to feed rivers during the dry season.
World grain harvests have fallen short of consumption in the last five years and stocks are at their lowest level for 30years.
"The world has been slow to respond to these new threats to food security," Brown said. "World food security is a far more complex issue today than it was a generation ago. In earlier times, if world grain supplies tightened, the US simply returned some of its idled cropland to production, quickly expanding the harvest and re-establishing price stability. That commodity set-aside program was phased out in 1995, depriving the world of this ready reserve of cropland that could be quickly brought into production."
He added that it is perhaps a commentary on the complexity of our time that decisions made in ministries of energy or by misters of water resources can have a greater effect on future food security than those made in ministries of agriculture.
"Many Americans see terrorism as the principal threat to security but for much of humanity, the effect of water shortages and rising temperatures on food security are far more important issues," said Brown. "For the 3 billion people who live on 2 dollars a day or less and who spend up to 70% of their income on food, even a modest rise in food prices can quickly become life-threatening. For them it is the next meal that is the overriding concern."
By David Hopkins