All life as we know it is dependent upon water. So obvious is our dependence that, when we search for life beyond our planet, we begin by looking for traces of water.

Our planet has evolved means of providing, saving and spreading fresh water. So accustomed to these mechanisms are we that we take them for granted, but as we survey other planets and moons, we get a sense of how remarkable they are. So it is useful to begin in thinking about water to see what “nature” has given us.

Sunlight hitting the surface of the earth acts as a giant distillery, lifting enormous clouds of fresh water from the salty oceans. In the form of rain or snow, this moisture is then dropped back on earth. The portion that falls on land is then either preserved in glaciers or ice caps, filtered into aquifers or sent along the courses of rivers seaward. So the process forms a cycle in the midst of which we live.

One of the greatest advantages humans have had over animals was our ancestors’ skills in interven- ing in this cycle by tapping, preserving and distributing water. Those skills have grown over eons, but the basic pattern that was first learned 6,000 or so years ago remains the same: water flowing down rivers was diverted into ditches that led outward onto land where crops could be grown or poured into basins where it could be “parked” until it was needed. Today, nations build huge dams that trap river water and store it in natural or artificial lakes from which canals or pipe lines distribute it over vast areas or channel it to distant cities. This complex of about 50,000 large dams and lakes makes up one of the greatest forms of human endeavor in our times.
 

Download the full chapter.

____

In anticipation of the Affordable World Security Conference William R. Polk's series of articles will provide a 'reader friendly' and insightful overview of conditions, developments and activities that are subtly but powerful affecting our daily lives.

For a list of published and upcoming articles, please visit the The Intelligent Citizen's Guide to His World overview page.