I go back and forth sometimes between two schools of thought on resource usage:
A) Conservation- resources are limited and must be saved (environmentalists, energy & water conservation, etc.)
B) Exploration & Development- the universe holds infinite resources and we should focus on finding new ways to exploit these rather than waste time on conservation.
Lately I have been leaning towards B. Mankind should focus on moving off-planet as quickly as possible and develop better technologies for mining & harvesting & using resources on our own planet as well as other areas of our galaxy and even the universe itself.
Conservationists believe that resource usage is a zero sum game. It is not. Oil companies keep discovering vast new reserves as well as ways to get much more oil out of fields that were once thought tapped out. Water is the most common element on our planet and if we can find better ways of purifying sea water, many serious issues facing the American Southwest and other areas of the world will disappear. Even the push against air pollution should be more about harvesting the bad elements out of the air then not producing them in the first place.