A recent study by the National Academy of Sciences indicated that man’s activities definitely have an impact on the face of the Earth. Ten percent of the entire land surface is used for cultivation to grow crops and 30 percent of the Earth’s land surface is under some form of use by man. Prior to the dawn of the industrial age when we substituted machines for human and animal power, our ability to influence our global neighbors was limited but at the time of the industrial revolution and at an accelerating pace since then, our activities can influence our neighbors thousands of kilometers away from us.