Even getting kids to just think about respecting nature, and nurturing the land and water is a great start. I'm volunteering at the local elementary school where we have a little veggie garden going, and we're teaching 80-odd kids each week about gardening. Hardly ever have a kid that's not interested and engaged. It's been an eye-opener for everyone and now we are in our third year.
You can teach a kindergartner that the leaves on a plant collect the sun to make the plant grow, and so the air needs to be clean for the sun to reach the leaves. You can teach a 5th grader the fascinating science behind it all. Photosynthesis to composting, they all just eat it up.
Find a kid and teach them gardening, by all means! My grandkids are in Salt Lake City, but I've already been planting things with the 2-year old when I visit and we have lots of fun getting dirty. She grew cherry tomatoes and some herbs in her earth box this summer.
