WHERE TO SHOP:
Make at least one trip per week to your local farmers' market. They have more than doubled in number over the past 15 years, to more than 4600 nationwide. (Visit localharvest.org to find one near you.) In addition to fresh meat and dairy, these markets sell produce that was likely picked within the last 48 hours. Just don't assume all of the offerings are organic. It's expensive to get certified by the USDA, so small farms can't always afford to. When they do, you'll probably notice that investment reflected in their prices. If you don't see an organic seal, ask the farmer whether she uses pesticides, synthetic fertilizers, or antibiotics. In other words, "Shake the hand that feeds you," advises Pollan.
YOUR GREEN GROCERY LIST:
Organic produce, starting with whatever you eat most often. Keep in mind the Environmental Working Group's "dirty dozen"—fruits and veggies found to have the most pesticide residue, even after washing: peaches, apples, sweet bell peppers, celery, nectarines, strawberries, cherries, kale, lettuce, imported grapes, carrots, and pears. It's fine to buy nonorganic, thick-skinned fruits like avocados, bananas, and pineapples.
Locally grown food. The fewer miles a piece of produce has traveled, the riper (and tastier and more nutritious) it will be.
Omega-3-rich fish. Cut your meat consumption in half and replace those proteins with fish like wild salmon and trout. Avoid farm-raised salmon (full of banned PCBs) and canned albacore tuna (loaded with mercury).
The Hard-Core Greenie You wear canvas kicks, charge your MacBook from inside your solar backpack, and keep a dog-eared copy of Alice Waters's The Art of Simple Food on your nightstand. You're passionate about reducing the environmental impact of your diet, and you're itching to get some dirt under your fingernails.
WHERE TO SHOP:
Augment your pantry by joining a CSA (community-supported agriculture)—a food co-op whose members buy "shares" in a local farm (generally starting at about $50 a month) and in return receive a box of its produce each week. The food doesn't get much fresher or more local. The downside: You get whatever they deliver, even if you can't pronounce it (it's kohl-rah-bee). Consider growing your own food. With even less than 200 square feet of outdoor space, you can harvest greens, tomatoes, cucumbers, and beans. Plant herbs in a pot on your fire escape—rosemary and parsley do pretty well year-round. Or take advantage of one of the 18,000 community gardens peppered across the country. To find one near you, visit the American Community Gardening Association website (communitygarden.org).