My favorite “environmental” Mitzvah is: Love Your Friend as You Love Yourself. What greater way to be nice to my friends than to do what I can to make sure they live in a clean, pristine, healthy, uplifting world?
Lifnei iyver lo titeyn mikshol-before a blind person don’t put a stumbling block. i.e., if someone is obese don’t put chocolate cake in front of them; if someone has poor sexual boundaries don’t wear a revealing outfit; if someone has no eyesight don’t put things down in their home where they wouldn’t expect them, etc.
Lo tachmod, “do not covet” (Ex. 20 / Dt. 5, to answer my own question!) — the world can sustain infinite spiritual & communal & personal growth, but not so growth in GNP and in ‘stuff’ — being happy with what we already have is a key eco-mitzvah.
At Adamah Adventures, we love teaching our campers “With your gear you shall have a spike, and when you have squatted you shall dig a hole with it and cover up your poop.” (Deut. 23.14) Jews have been practicing LNT for thousands of years!