Agree or disagree with him, you have to respect the guy. And anyone who’s that healthy at 81 years old has got to be a pretty strong endorsement for his style of healthy living. He’s been a pretty great advocate for the environment, and his latest campaign is called, subtly enough, the “Nature Challenge.” He offers up 10 ways to live more sustainably, and for the most part they’re simple and sensible. You can sign up for the challenge here.

1. Reduce home energy by 10%

2. Eat meat-free meals once a week

3. Buy a fuel efficient, low-polluting car

4. Choose an energy efficient home and appliances

5. Stop using pesticides

6. Walk, bike or take transit to regular destinations

7. Prepare your meals with locally produced food

8. Choose a home close to regular destinations

9. Support alternatives to the car

10. Get involved, stay informed

Some of them are pretty big, and easier said than done - buying a new house, car or major household appliances is a big deal - but something like turning down the thermostat, eating less meat, or walking more is downright simple. Petitions are the lowest form of democracy, but you might as well sign up and be another drop in the bucket, for all the effort it takes.