Insights · May 7th, 2007
This is a guest blog entry from our writer, Mark Safford.
One of the major problems with greenhouse gases and global warming is that they are seriously disrupting the world’s water cycle. This is that massive, complex system by which water is evaporated from the surface, rises to clouds, and falls again as precipitation, usually at a quite different location from where it evaporated. In some cases water stays in the oceans, lakes and rivers for a long time, in other cases it may stay locked up in polar or glacial ice for centuries. In other cases it is recycled quickly and repeatedly through this cycle so that we can use and reuse the same molecules of water again and again in a short period of time to drink, to water our crops, to swim in, to bathe in, to flush with, and so on. This is the basis of our globe’s weather pattern of rainy and snowy days, growing seasons, floods, monsoons, hurricanes, and so on.
We have developed a modern civilization of 6.5 billion people based on our ability to exploit this water cycle to tap it for human use. It affects where we have chosen to build cities, where we grow crops, where we herd animals, where we build reservoirs, where we irrigate, where we navigate in boats. In short, it is a big factor behind how we each choose to live. However, that cycle is now being disrupted in many ways. Temperature patterns are changing; precipitation patterns are changing; storm patterns are changing; ocean currents are changing; water levels are changing. And all of these changes are also affecting the quality of our lives.
Andrew Revkin’s story in the April 1, 2007 New York Times points out quite clearly how the developed world can afford to adapt to these changes much more readily than the poorer worlds – places like Malawi, India, and others. The US and Canada can do much to adapt to such events as falling water levels in the West and changes to rain patterns for farmers in the Great Plains, but subsistence rain-dependent farmers in Africa and India cannot do the same.
Scientists believe the world has a constant amount of water, but that it exists at any one time in various solid-liquid-gas and fresh-salt proportions. Human life is ‘good’ when there is sufficient fresh liquid water to meet our total needs. The problem is that climate change alters the proportion of liquid fresh water and its location. Some regions of the world end up with less, and others end up with more. When this becomes chronic through regular droughts and/or flooding, the quality of life for people in those regions is seriously affected. And this is happening more and more across the planet.
The same process applies to dangerous weather, such as tornados, hurricanes, typhoons and other severe storms. These are increasing in frequency and severity. I am not saying we will run out of water; but we will face growing shortages of sufficient fresh liquid water to meet the needs of populations in certain regions of the world. When this happens, again the developed nations will be able to cope much better than poor regions.
Will there be wars over water supplies in the future? It is possible. Will there be massive population migrations spurred by these weather changes? They are already happening, and will continue to do so. Imagine what will happen when sea levels rise to the point where entire nations like Bangladesh and island countries such as the Maldives, Tonga and the Bahamas – or areas like Florida – find more and more of their territory under water. At what date in the future will an old oil tanker pull up to a polar ice sheet, start melting it and pumping the fresh water on board to be sold to the highest bidder in the tropics? Maybe it has already happened . . .
Thus, when we think about the future of our planet and energy supplies and talk about the ‘end of oil’, there is another liquid which we must also consider. And that is water.
U.S. EPA article on climate change’s health and environmental effects
Pacific Institute article on impact of climate change on U.S. water supply