One way to cut carbon footprints is to use more locally made products, even for “little things” like toiletries. These soaps are made by Creation Farm, near Frankfort, Mich.

Here’s a question for those who want to cut their carbon footprint: What is the better wine choice-a bottle of French Bordeaux, or something from the Napa Valley?

Daniel Goleman’s new book, Ecological Intelligence, can help answer all sorts of questions like that. He writes about something called “life cycle assessment,” or LCA, a discipline that blends industrial engineering and chemistry with environmental science and biology.

Mr. Goleman’s book can help us make informed choices about the true environmental impact of the stuff we buy.

It is not always an obvious choice. In the case of Bordeaux vs. Napa, the French wine is the better choice for those living east of Columbus, Ohio; for those to the west of Columbus it’s the California wine. That is mostly because it is so much more efficient to ship by ship than by truck.

LCA takes into account all those hidden impacts, from the extraction or fabrication of the ingredients, through manufacture, transport, sales, use, and on to disposal.

Once people understand the full impact of their purchases, argues Mr. Goleman, they pick the best options. This creates the feedback loops to producers that inform the production of better options.

He offers an example of a feedback loop at Skin Deep. The site is the Environmental Working Group’s safety guide to cosmetics. One of the surprising things, says Mr. Goleman, is how bad some of the best-sounding brands and products really are.

I went to see for myself, and was completely overwhelmed by information. I just wanted to find a decent, conscionable shampoo. But, Looking at the site, I decided that finding a good one on their list that is also carried by one of the stores I frequent was a task I could put off for a while.

Just days later, however, I received a newsletter from the Organic Consumers Association that summarized the data. This was a big improvement, but it gets better!

Later in the same week I went to the Winter Farmers Market at the Mercato, at the Commons in Traverse City.Creation Farm has a shop there. Mike Hubert and Anna Sangemino sell herbal remedies and soaps with simple ingredients that you can pronounce. (Look at your bottle of eco-shampoo and see if the same is true.) The two grow a lot of the ingredients themselves, in a hoophouse near Frankfort.

They know a lot about soap, so I asked Mike, “What is the difference between soap and shampoo?”

Like anyone who is knowledgeable and passionate, he gave me a lot more detail than necessary. My next question was more careful: “Do you have shampoo?”

They did, and Mike suggested the rosemary shampoo. “Depending on the cause, it can help reverse premature baldness,” he said. I have reached an age that hair loss can’t be considered premature. Of course, I took it!

Jim Sluyter leads the Michigan Land Use Institute’s Get Farming! project. Reach him at jimsluyter@mlui.org.