Are We Running Out of Water?
Approximately 440 million people in 29 countries are currently facing extreme shortages of water. Twenty percent more water than is now available will be needed to feed the over three billion additional people who are estimated to be living by the year 2025. As shortage of water much as two-thirds of the world population could be water-stressed by then.
Aquifers, which supply one-third of the World’s population, are being pumped out faster than nature can replenish them. In 1950, the U.S. took 12 trillion gallons of water from the ground by 1980 the figure more than doubled and is still increasing at an alarming rate. The Ogallala Aquifer is being depleted at a rate of 12 billion cubic meters (420 billion ft3 or 9,729,000 acre feet) per year, amounting to a total depletion to date of a volume equal to the annual flow of 18 Colorado Rivers (Its flow is 4000 cubic feet per second). Half the World’s rivers and lakes are seriously polluted. Major rivers, such as the Yangtze, Ganges, and Colorado, no longer flow to the sea for much of the year because of upstream withdrawals.
Where Are the Water-Scarce Regions?
Water is unevenly distributed across the populated regions of the World. It is an irony of geography that two-thirds of the World’s population lives in areas that receive only one-quarter of the World’s annual rainfall. By contrast the most water-rich areas of the world, such as the Amazon and Congo River Basins, are sparsely populated. Some of the most densely populated regions of the world, such as the Mediterranean, the Middle East, India, and China will face severe water shortages in the coming decades.
Even areas of the United States (particularly the southwest and parts of the midwest) are vulnerable to water shortages, as the media attention to the ongoing drought in California attests. Currently, the San Diego water authority is threatening a moratorium on the use of municipal water for irrigation, washing cars etc.
In 2004, the U.S. Geological Survey was claiming this drought to be “comparable to or more severe than the largest-known drought in 500 years.” With the scarce rainfall received since the early 1990s, plus low snowpack in the Sierra Mountains, which supplies the Sacramento-San Joaquin River Delta including the Rockies, the source of the Colorado River. All this has created the foundation for “the perfect drought” so serious that it just might reclaim the desert that this area once was. Sadly, this trend is evident in many regions across this country and around the world.
Agriculture In a Water-Starved World
Limited or non-existent water supplies will be the primary obstacle to increased food production in the next few decades. In the past, prior to the onslaught of climate change, most of the increases in agricultural productivity occurred on irrigated lands, since irrigated farmlands are five times more productive than rain-fed. Today, according to Worldwatch, “irrigation-fed agriculture supplies about 45 percent of the World’s food supply”.