Guess what? We don't need to "save the earth." Yep, I said it out loud.
This planet is not dependent upon us for its existence. We are the passengers. Whether we believe it, deny it, or bitch about it, we are the dependents. The earth could go on without us.
According to the Field Museum of Chicago, there have been five major extinctions within the accepted western history of our planet. In addition, alternative history proponents like Graham Hancock, Randall Carlson, John Anthony West, and others say that humans have gone from an advanced society to nearly being wiped out before. It can happen again.
Humans can't live off of a barren rock. If our ecosystems die, we die too. If we fail in our role to be good stewards, the next time around maybe the praying mantis will be the dominate species.
When you hear others say "Save the earth," what they really mean is "Save humanity." And how do we do this? First you must save yourself. Get your own life in order. When you change your focus to what you want, that's what expands.
Don't expect the world to change. Be the change you want to see in the world.