In 2008, a middle school class came to our farm as the inaugural class of “Roots — Where Do Things Come From and Where Do They Go.” Designed to trace the life cycles of everyday products, the class investigated topics like water, transportation, waste, and food.

The students then discussed their research about the benefits of self-sufficiency. Why should we grow our own food? Blaise provided the most obvious answer: “Simple. Then we wouldn’t have to depend on the mainland.” John added, “We can help reduce the amount of gas that is used from ships to bring food here by trying to grow more crops.” Alec then made this point clear: “Because gas prices are high, shipping from a farm on the Big Island will use much less fuel than shipping from Mexico.”

Megan had found out that “four hundred gallons of oil are used each year to feed one American, and 31 percent of that oil is devoted to producing the chemical fertilizers so plants will grow better. We don’t need to hurt the environment by using artificial fertilizer. We can use natural fertilizers like mulch, manure, or compost.” Katie then pointed out that growing our own food “can help Hawaii’s economy because the profits on the produce will go right back to the people of Hawaii instead of going to a corporation on the mainland.”

Mika talked about the quality of what we eat: “Our produce would be fresher. We could just go to a store and buy a tasty fruit or vegetable that has not been sitting in a container for days or even weeks.” Another student had her eye on diversifying our employment base: “Farming opens up more job possibilities for the unemployed in Hawaii, and offering college students courses for this occupation would ensure farming a safe place in tomorrow’s economy.”

These students learned a lot more than how to weed a taro patch.

Where are we going?

Global warming from nitrous oxide, the continued heavy use of herbicides and pesticides, especially in foreign countries, that make farm work one of the most dangerous occupations — these and other external costs don’t show up in the price of food. In 1929, Americans spent 23.4 percent of their income on food. Now it’s just 9.8 percent. The world still eats mostly the four super crops — wheat, corn, rice and soybeans — and animals consume one-third of production.

Of course, we must have our sugar — about 100 pounds per person a year — and oil is still cheap enough that food can be shipped all over the world, helping poorer countries displace subsistence farmers with monoculture so that produce can be sold to high-end customers in high-end nations. This is also why a nation like Brazil is clearing 8,000 square miles of forest a year.

Does it make sense to pursue self-sufficiency in our island home? All of this information indicates that we must. Nainoa Thompson often talks about Hawaii as a model for the world. When people finally realize that planet Earth is a closed system, our “island mentality” can inform all. If the world is made up of many “islands,” each “island” is in trouble when the food production and distribution systems they rely on are unsustainable.

Here are the global and the local problems: a growing population, increasing urbanization, degraded farmland and destruction of important ecosystems for more farmland. On a global and a local level, we need to control population growth, or at least not encourage it by pushing urbanization, especially of farmland, and we need to farm in more sustainable ways. The old slogan, “Think Globally, Act Locally,” is still relevant. See and understand the big picture, how we are part of it, and work for changes at a local level.

Small steps towards sustainability

Organizations focusing on diet change and food security are springing up everywhere. There are more and more school and backyard gardens, which may provide one of the most important answers to the questions of who will farm, and how.

We need to get good affordable food to lower-income families. We need to reduce synthetic nitrogen use, mitigate the external costs of conventional agriculture and improve soils by using more organic matter.

None of these will raise farmers’ profits; in fact, they all translate into more labor. So maybe it doesn’t work to have 1.6 percent of the population of Hawaii doing agricultural production, and it doesn’t work to keep bringing in poor people from other nations to do the work.

Maybe we need to see how much of an agrarian society we can become again. That might just be possible in backyards, schools and community gardens. Maybe building permits could be contingent upon putting in garden spaces. Maybe tax breaks could be given for gardens as well as for solar energy.

After all, America now has 25 million acres of lawns. Green waste, now available at only a few sites, could be made available in every community. Many backyards could accommodate chicken-tractors and fish ponds — of course, restoration of some of the very productive historic Hawaiian fishponds has been underway for years. What about a fast-food restaurant chain with only local food? Health-care providers could discount premiums based on steady weight reduction.

These are not really new ideas. Many have been tried before, but never before has the urgency to act been so great. The first people of Hawaii took advantage of a very rich ecosystem, much of which remains. Their methods particularly suited to this ecosystem for cultivating an older brother who fed them well are legendary, but the older brother has been largely absent from most people’s lives for too long. All of us who live here could benefit by his resurgence.