Giving back to the earth

I went to a talk recently about breathing. I am interested in breathing (apart from the obvious reason of staying alive). Anyway, the speaker talked about a technique where you breathe in energy from the earth through your feet, take it up through your body and then breathe it out through the top of your head. A common enough breathing exercise that I have come across at other talks and workshops.
But now I think - haven't we taken enough energy from the earth already? How about giving some energy back to the earth? At a yoga weekend once, we were introduced to an exercise where we imagined breathing in all the 'black' of the world (ie negativity, impurities etc) and converting it to 'white' (positivity, goodness, purity etc), then breathing it out into the world again. Many people at the workshop objected to this exercise. It was not a good PR tool. But I think the so-called 'new age' too often has a 'what's in it for me' approach that is about more of the same - not giving but taking.
So let's focus on what we can give back to this ailing world of ours, be it energy, love, or just plain old respect.