The Case for Gardening as a Means to Curb Climate Change

I am quite possibly the world's worst gardener. I would like to blame my yard for this. It's full of shade, and the shade comes from walnut trees, which, as any gardener worth her salt can tell you, exude from their roots a substance called juglone, whose job it is to take out the competition by wilting the neighbors. So, my garden now has raised beds. These are supposed to help keep the tender roots of the garden plants away from the death-peddling juglone below. Of course, the problem of the shade remains. But I am a new gardener, and I am determined to keep at it. So far, I have grown impressive crops of mint, parsley, and lettuce. I once harvested enough peas to feed all four of us. One meal. As a small side dish.

I am upstaged in the gardening department by my own compost pile. All kinds of things take root in it. Two years ago, some member of the squash family -- possibly a cross-pollinated wild hybrid of some kind -- planted its seedling flag atop the steamy, south-facing slope and began to grow. Soon, its stickle-backed leaves were the size of placemats, and they were attached to a stem as thick as a child's wrist. When it started to climb the sides of the bin and spill over the top, blooming wildly with crepe-y orange flowers and shivering with bees, Elijah became so terrified that he bribed Faith into taking over his every-other-night compost-toting duty.

Elijah, you are scared of a squash vine?

It tried to grab me. I am NOT kidding. Please! You can have all my allowance.

When we came home from a camping trip, Elijah ran into the backyard to check on the compost predator.

Mom, come and look! It turned into a balloon tree!

And so it had. Grabbing hold of a tree trunk next to the bin, the vine had climbed a small maple and entirely covered it. Its flowers had become fruits -- deep green globes, each the size of a party balloon. And so we had squashes -- or something -- dangling above our heads. They tasted good. I sautéed them with garlic and basil, grated them up for soup stock, added them to muffins and pasta sauce, and, in one form or another, we ate them all winter.

If only my garden were half as prolific. To be sure, I'm mostly slumming when I'm working in it. Because our CSA farm is only a half-mile away -- and its hoop houses, hen houses, and root cellars provide us eggs and produce year-round -- I have the luxury of leaving the serious crop production to the experts and can still carry into my kitchen (via bicycle or sled) locally grown food, burning no carbon to do it.

It's likely that your garden will produce a much bigger fraction of your groceries than mine and thus save fossil fuels twice over -- first, in the form of long-distance, refrigerated produce transportation and, second, in local trips to bring the food from market to kitchen. Regardless, the real climate value of the garden lies in three other places. The first is in building skills. If our children are going to grow up in a world of increasing environmental instability and declining oil reserves -- and they are -- it seems useful for them to know a few things about potatoes.

The second is in preserving the genetic diversity of seeds. In an unpredictable climate, we need as many varieties of as many fruits, grains, and vegetables as possible -- the drought-resistant ones, the mildew-resistant ones, the early-blooming and late-blooming kinds. Big commercial seed companies are, for the most part, not interested in the rare, the peculiar, and the untruckable. As a result, many traditional varieties are now on the edge of extinction. But gardens can function as living archives of genetic diversity, especially when backyard gardeners become seed savers. With almost no extra effort on your part, your garden can feed your family while also doubling as a gene bank.

As I think you can see, this is sounding pretty heroic already: Son, I need your help in the garden today. Our job is to preserve 10,000 years of agrarian heritage.

The real carbon savings of gardens, however, comes from the compost, and this is the reason I am issuing a universal recommendation for gardening. Together, food waste and yard trimmings make up 26 percent of the municipal solid waste stream in the United States. And, when buried in landfills, they become fuel for the production of methane, a long-lived gas that is 23 times more powerful than carbon dioxide at trapping heat. According to the U.S. Department of Energy, methane is now fully 10 percent of all U.S. greenhouse gas emissions -- and its slice of the emissions pie is growing. Furthermore, of the 13 major sources of methane, the largest single one is landfills. (At 184.3 million metric tons per year, landfills add more methane to the atmosphere than "enteric fermentation," which refers to, well, how the nation's 100 million cattle add methane to the atmosphere.)

Rerouting one quarter of the waste stream to compost bins would seriously tamp down the number one source of methane gas emissions. And, because it serves as fertilizer for the garden, compost obviates the need to purchase synthetic fertilizers, which are manufactured from fossil fuels, and which, when used as directed, add a second noxious greenhouse gas to the air: nitrous oxide (whose heat-trapping powers are 300 times more potent than carbon dioxide; it is also a precursor of smog).

So, to summarize: By planting a garden, you create the need for compost, and by starting a compost pile, three problems are solved:

1. You direct food scraps away from the methane factories called landfills.
2. You make homemade fertilizer with no fossil fuels.
3. You prevent the formation of a smog-making, heat-retaining gas.

And the best part of all: The compost pile, nature's Crock-Pot, requires almost no work whatsoever. Within months, dead leaves and old food will, all by themselves, transform into rich, black, loamy (non-smelly) humus. Depending on your perspective, this is either a holy blessing or the result of unpaid labor on the part of earthworms, fungi, and other members of the ecosystem service industry.

Depending on how you run your household, you can either send your eight- and five-year-old out to the compost pile on alternate nights, armed with a flashlight and a bucket of food scraps, because come on now, we all have to pitch in around here, or you can pay them.

And depending on your relationship to the various food-providing institutions that surround you -- churches, temples, hospitals, schools, nursing homes, restaurants -- you can go public with your newfound skills and make monumental changes. Bates College in Maine composts all of its dining hall food scraps and returns them to the farmers' fields that supply the (organic, local) food that is served there. The city of San Francisco has already instituted mandatory, curbside compost pick-up for urban residents. In short, the large-scale diversion of food scraps from methane-generating landfills is a doable project that awaits no technological breakthrough or venture capital investment. So, go do it.

Excerpted from Sandra Steingraber's Raising Elijah: Protecting Our Children in an Age of Environmental Crisis (De Capo Press)