With just a little thought, it's easy to make your trips to the supermarket a little greener. Start by first checking out which stores near you have tried to adopt eco-friendly practices--if they avoid energy-hogging open-air refrigerators, for example, use efficient lighting, or have solar panels on the roof. Once you start shopping, here are a few ways to reduce your grocery shopping carbon footprint in no time.

1. Skip the canned and frozen foods. Stick with fresh vegetables, when possible, and dried legumes that you can soak yourself. Freezing and canning food are both energy-intensive processes--both in preparing the food and then packaging it. So go with fresh produce (it retains more nutrients, and tastes better anyway) or preserve your own!

2. If milk is on your shopping list, try a dairy-free substitute. Dairy production requires an incredible amount of water--for the cow to drink, to raise the grain (or hopefully, grass) it needs to eat, and to process the milk. It also creates tons of solid waste (guess where that ends up) and methane, which is an even more potent greenhouse gas than carbon dioxide. Give nondairy products a shot--they're often healthier, anyway, since they're lower in fat and cholesterol, plus they'll last longer in your fridge! Supermarkets these days have exhaustive selections of soy products (if you read the label closely enough, you may even find ones made locally), or you can get creative and make things yourself, like your own almond milk.

3. For much the same reason, find substitutes for whatever meat is on your list. My boyfriend (who is not a vegetarian) had his entire (also non-vegetarian) Superbowl party unknowingly eating vegan chili and loving it. He didn't have a chance to tell them until after the game, when they asked for the recipe because it was so good--Smart Ground did the trick!

4. Forget the cleaning products--make your own! You'll have an easier time finding locally-sourced ingredients than brands that manufacture nearby. Plus, you can customize your own scents, and if you go to the effort of making your own blends, you'll probably go through less product--saving money and cutting down on waste at the same time. Start with these 8 cleaning product recipes.

5. Buy in bulk. If you have to buy products in disposable containers, go for the larger size and portion out later. You'll save money as well as cut down on packaging. Even when containers are recyclable, reducing waste is always the better choice. (Remember the three "R"s? Reduce and reuse come first.)

6. And finally--your packaging. When you go to pick out those fresh veggies, or if you buy things like grains and cereals in bulk, avoid the small plastic bags at the store. You probably have your own at home without even trying--why not reuse those? (Think: the bread you bought last week probably came in a plastic bag that's now empty. Perfect to put some string beans in. Or anything else--even berries, if you're buying by the pound. And why not re-purpose the bags your newspapers come in?) Of course, you can also bring small canvas bags with you--reusable bags have become a no-brainer for carrying groceries home, but how about bringing the habit inside the store as well?