I found this really interesting. One of the areas that I'm studying is Judaism and ecology. I came across this blog entry, and it definitely made me think. We usually use the word "sustainable" in terms of green living. Here, that philosophy is applied to spirituality.
It's actually a really strong metaphor. There are people who go to pretty extreme lengths to make environmentally ethical decisions. They buy specific products, avoid certain activities, and are conscious of their impact on the planet.
These are wonderful things to do, and I do them to the best of my ability (and budget).
I think religious devotion deserves those same standards. The Torah asks that of us.
It also asks us to be ethical stewards of the earth.
This just happens to dovetail nicely. Torah certainly is a tree of life.