World Water Day focused on important natural resource
A United Nations report out today says that polluted water kills more people than all violence and war combined.
One finding of the report is that three liters of water are needed to make just one liter of bottled water. The bottled-water industry in the United States uses 17 million barrels of oil each year. Sandra Postel is an international water expert and is the National Geographic Freshwater Fellow in 2010. The April 2010 special issue of National Geographic is called âWater: Our Thirsty World.â
We live on a very water-wealthy planet. Itâs hard to believe we would have a water problem, but 97 percent of the worldâs water is sea water. Itâs in the oceans. And so itâs too salty to drink. Another 2 percent of the earthâs water is locked up in glaciers, and icecaps, and so we canât access that for drinking, either. So itâs less than 1 percent of all the water on earth that is fresh, and water that we can think about using for drinking, and the other needs that we have. So itâs a very tiny share of all the water on earth.
Q: And how is the supply changing?
Well, the supply is the same. You know, we have the same water on earth now as existed when the dinosaurs roamed the earth. So the absolute amount hasnât changed. But what has changed is that we have more people, and more agriculture, in places that are very water-stressed. And so itâs sort of a mismatch between where the demands for water are and where the supply of water is. And so in more and more regions, we find that weâre sort of running out of that local supply. Rivers are running dry; groundwater supplies are being overtapped and depleted. And so itâs a question of whatâs happening locally and regionally as much as globally.
Q: Is this affecting international issues?
It is affecting international issues. You know, many rivers run between two or more countries. You know, there are about 260 rivers around the world that are shared by two or more countries. And so as countries build dams, and divert more river water, there can be some tensions arising between their neighboring countries. And so we see this in the Middle East; we see it in the Tigris and Euphrates river basins between Turkey, Syria and Iraq. We see it in the western United States, among the states and with Mexico, where the Colorado and Rio Grande rivers are shared among various states in the western U.S. and with Mexico. So these are important issues. And itâs all about sharing that water, and we donât yet in many cases around the world have a treaty that says, âHow should we share that water?â And so until we get to a good water-sharing situation, we can see a lot of tension over water.
Q: Can you give our listeners an idea of how aquatic species are affected by this?
Yes. Thereâs an incredible concentration of life within fresh water. If you look at rivers, lakes, wetlands, our freshwater ecosystems, they make up only about 1 percent of the earthâs land surface. But they contain nearly as many fish species, for example, as the entire oceans do, which make up 70 percent of the earthâs surface. So thereâs a real concentration of biological diversity, of species diversity, within fresh water, and many of them are at risk of extinction. Forty percent of the fish species in North America now, for example, are to some degree at risk of extinction because of the way weâve managed rivers: the pollution, the damming, the diverting of rivers. And this has increased a lot just in the last couple decades. Weâve gone from 20 percent to 40 percent at risk just in the last couple of decades. So this is a real serious concernâand again, something we can do something about if we manage dams differently, if we reduce pollution, if we begin to let rivers run like rivers again where we can, and restore that kind of habitat, so those species can survive.
We will bring you part two of this interview tomorrow, where we focus on water issues in Florida.comments powered by Disqus