We think of innovations in cars or computers, but rarely of innovations in farming and food. Yet a new type of farm has caught on rapidly in recent years, in both America and Europe – Community-Supported Agriculture, or CSA.

CSAs are small farms owned, jointly, by a nearby community, and that supplies food for people who live nearby. Sometimes townspeople will buy a plot of land close to town, hire a farmer to work it for them, and share all the crops. Other times the community can sell the surplus for a profit.

In some circumstances the farm is affiliated with a farmer’s market that sells the produce back to local people, giving the town a source of civic income; in other cases, townspeople simply own shares in the farm and get part of the harvest as profit. Still other times the farm is more like an allotment, with families owning their own sections. There are almost as many models as there are farms.

Such community ventures solve many problems at once. First, they find a use for plots near towns that otherwise might go unused. They provide work for farmers in an age when their numbers are diminishing – and if the community hires young people as hands, they give wages and rural skills to local youths.

In an interview with Global Public Media, community farmer Jay Martin made the point that many farmers must go deeply into debt in order to begin or keep farming – and when they have a successful crop, he says, they must deal with transport and the uncertainties of the market. When he turned his farm into a CSA, on the other hand, the costs were covered by the community, and he had no transport costs and a built-in market.

Turning a local farm into a CSA also means giving one’s money to local people means that the money keeps circulating nearby, rather than going to faraway corporations. It means that your food comes from people you know and trust. It means that people near you are getting work and staying fed and housed, which benefits your local community.

But perhaps the most important use of such farms is keeping local areas self-sufficient. We are surrounded by fertile land here in Ireland, yet we import most of our food. If there were another oil crisis, or a war, or any other kind of emergency, we would have to rebuild a great deal from scratch.

Food transported from one kilometre away, rather than 10,000, eliminates a major source of climate chaos and pollution. At present, many foods must be sealed in plastic and foam packaging, sometimes preserved in chemical gases, to delay spoilage, and even the healthiest vegetables are less nutritious after sitting on a shelf for weeks. If the farm is next door, the food is always fresh, and no rubbish need be generated. In an age when fewer people feel part of a community, a CSA allows people to invest in a project together, with their neighbours, and share in the rewards.

When I worked at a magazine in America, our business bought shares of a CSA, and they grew a variety of crops for the shareholders. As one crop after another came into season, they sent us boxes of whatever vegetables we had earned by our share, so we got weekly deliveries of rutabaga, beans, corn, onions, rhubarb or whatever was ripening. This was in Minnesota, up near Canada, so the growing season was quite short, but we got plenty of food for our money, and the farm stayed in business when so many others went under.

Finally, it gave young urban people a chance to experience foods they might not have ordinarily, and to learn to cook things they could not, at first, identify. Many of the office workers, I suspected, had grown up on a diet of takeout and crisps, and didn’t know what to do when they first saw a kohlrabi. When I peeled the skin off and at it like an apple, though, they tried it as well and were hooked. I had to caution them not to try it with celeriac, however – not all roots are the same.

Of course, Ireland cannot import all its foods – we won’t be growing any bananas here for a while, climate change or no, and even local food is not always in season. But simply cutting our imports can make a big difference in many areas — the difference for some people between having a job, or having enough food in a crisis, or having hope.