A frequently overlooked area when it comes to greening your life is greening your pet's life. This can be a tricky subject, since what works best to keep your pet healthy and happy may not always be an ecofriendly decision. Luckily, there's easy ways to make sure that Fido leaves a lighter pawprint.

Where you get your pet can have the biggest overall impact. Rescuing a pet from a shelter or the Humane Society gives an already existing pet a good home and the possibility of a happy life. Why pay a breeder to create another animal? Accordingly, heed Bob Barker's sage wisdom: remember to help control the pet population; have your pet spayed or neutered.

Just like human food choices, your pet's diet has an impact on our environment. However, pet owners know that diet is crucial to your pet's health, and can be very particular to a pet. Always check with your vet when changing pet foods. That being said, there are organic, humane, and sustainably-produced pet foods on a market–in fact, it's a fast-growing niche. Whole Foods, Wild Oats, and Trader Joe's have their own lines of pet foods, and there are plenty of other sources online.

All that food has to go somewhere, as pet owners know. Pick up your dog's poop with biodegradable doggy bags. Better yet, compost it. Yeah, yeah, I know you aren't supposed to compost pet waste. However, that rule generally goes for compost that is going to be used on edible plants, like a veggie garden–using that compost on landscaping or flowerbeds is fine. If the thought of adding poo to your pile still makes you cringe, create a whole separate compost just for pet waste. Bury a metal garbage can for a securely-contained poo pile. For your feline friends, avoid clay-based litters–the clay is strip-mined, and the dust from the clay can irritate your cat's lungs. A much more sustainable choice is Swheat Scoop, a wheat-based scoopable litter. Should your precious pal leave a not-so precious present for you on the carpet, there are plenty of eco-friendly pet-odor eliminators, from such companies as Mrs. Meyer's.

Finally, choose greener pet items when shopping for your pet. Scratching posts, toys, and leashes all come in more sustainable varieties. GreenPeople.org is a good resource for finding various vendors.