Wednesday, October 08, 2008

Population Growth Puts Dent In Natural Resources

ScienceDaily (Oct. 7, 2008) — It's a 500-pound gorilla that Robert Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, sees standing on the speaker's dais at political rallies, debates and campaigns. Its name is population growth.

"Population growth is driving all of our resource problems, including water and energy. The three are intertwined," Criss says. "The United States has over 305 million people of the 6.7 billion on the planet. We are dividing a finite resource pie among a growing number of people on Earth. We cannot expect to sustain exponential population growth matched by increased per capita use of water and energy. It's troubling. But politicians and religious leaders totally ignore the topic."
A major focus for Criss and his associates is the origin, character and behavior of river and floodwaters in the Mississippi, Missouri and Meramec River basins. Since 1990, the mid-continent experienced floods of such severity that they would not, under normal circumstances, be expected to have all occurred in a period of less than several centuries. Criss and a colleague have proven that engineering modifications of waterways have increased the frequency and severity of floods on most Midwestern rivers.
The United States is experiencing rapid population growth — at a rate higher than almost any other developed country — along with increased food production, Criss says. In many areas, especially the West, the practice of "mining" ground water to irrigate arid or semiarid land, which won't work in the long run, is becoming commonplace. "Energy and water use are intimately related," he says. "As water tables decline, you have to use more energy to lift the water out of the ground. That's what a pump has to do in places like Arizona where water levels have dropped many hundreds of feet. More people, more water use, more food, more energy. It's not sustainable."

Criss says approximately 150 million Americans use ground water, most of which is nonrenewable. When a well cannot pass drinking water standards, it is shut down and another one is drilled. Ground water extraction leads to dropping water levels in many places, and subsidence (saltwater intrusion) in others. The latter is the case in some of Florida's coastal cities, where salt water mixed with ground water has made drinking water unpalatable.

"Ground water, fossil fuel resources, cropland and forests are all being depleted or degraded," he says. "Thoughtful arguments can be made that for a sustainable world, we already have too many people, far more than can live by decent standards."

He says that, worldwide, the rates of increases of water and energy use have risen faster than population growth for the past 50 years. The fertility rate has actually lowered in much of the world, but the United States rate of 2.1 children for every woman of child-bearing age between 15 and 49, is now not much below the world's average, which is 2.6.

Despite what might appear as progress, Criss is disappointed that the United States has not contributed to the United Nations Population Fund for the past seven years. The Population Fund, begun in 1969, enables people in participating countries to learn about population growth and reproductive health.

"These U.N. projects have made great progress without any help from the United States." Criss says. "Many countries are seeing reduced growth rates. Africa still has a bad problem, but things are not as bleak as seven years ago. There are many medical, logistical and environmental reasons that these efforts should be supported. It's a considerable embarrassment to me that my country isn't chipping in."

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