Are you "giving back" at least as much as you "take"?

I am reading Ishmael, in which it proposes that most modern humans beings are captive to their “taker” society. If it is true that we are captive, is it even possible for us to be able to fully give back? If we keep taking without giving back we will eventually deplete our natural resources which support life as we now know it.

So, are you a minimal strain on earth’s natural resources? How?

http://en.wikipedia.org/wiki/Ishmael_(novel)