Most institutions, such as the food aid NGOs or the US Department of Agriculture, express concern about food security in terms of the ability for poor people to purchase adequate food. The USDA, for example, measures food security by asking households a series of questions (http://www.fns.usda.gov/fsec/FILES/FSGuide.pdf), including:

Q1 Which of these statements best describes the food eaten in your household in the last 12 months: we always have enough to eat and the kinds of food we want; we have enough to eat but not always the kinds of food we want; sometimes we don't have enough to eat; or often we don't have enough to eat?

Q1a (IF SOMETIMES OR OFTEN NOT ENOUGH TO EAT) Here are some reasons why people don't always have enough to eat. For each one, please tell me if that is a reason why you don't always have enough to eat.

Not enough money for food

Too hard to get to the store

On a diet

No working stove available

Not able to cook or eat because of health problems

Income-based Food Security

This is a valid way to think of food security. If food prices are high relative to income, or if other compelling expenses such as housing, health care and transportation also require a large portion of income, then securing adequate food on an individual or family level will be problematical. I will refer to this kind of food security as "income-based food security." Personal misfortunes or failings, structural economic inequality, recessionary business cycles, and monetary crises are examples of conditions that cause or exacerbate income-based food security. Asking heads of households is a proper way to understand this class of food security.

In general, households don't actually produce food, nor do they move food from producers to markets. Given current environmental and resource trends, the income-based food security perspective has some gaping blind spots. Instead of just asking food eaters questions, should we also be querying food producers, distributors, fertilizer manufacturers, supermarkets, energy experts and climatologists?

Distribution-based Food Security

Globalization of food commodities has greatly distanced food consumption from food production. Most people in industrialized nations, and quite a few in poor but food importing nations, are therefore highly dependent not only on the ability to pay, but on the ability to distribute food from places of production, storage, and processing to retail and home. Absent either the liquid fuels for shipping vehicles, or sufficient roads, rails and port infrastructure to carry and receive cargo, food becomes scarce no matter how much money someone has in their wallet. Examples include a place after a natural disaster or a war (Gulf coast post-Katrina), a nation embargoed for political reasons (Cuba in the 1990s), and acute shortages of fuel or trucks (UK trucker strike in 2000, Italy recently). With transportation disruptions grocery store shelves can go bare within days. I will refer to this kind of food security as "distribution-based food security." Just-in-time delivery systems, oil depletion, violence in oil producing regions, and "acts of god" threaten distribution-based food security.

Production-based Food Security

Total food output has increased dramatically over the past 50 years, far outpacing even the rise in population. The reasons for this increase in production, however, and the broader environmental costs incurred, suggest that food production will flatten and perhaps decline in the coming decades. Productivity gains were driven principally by increases in non-sustainable inputs, such as irrigation water from depleting aquifers, nitrogen fertilizer from natural gas, and greater mechanization in general requiring more fossil fuels. None of these are sustainable solutions, meaning they are bound to fail in the end without ample and timely substitutes. Cultivation, irrigation, fertilization, herbicide and pesticide practices have also led to massive erosion of topsoil, leading to a steady decline in the quality of the land base supporting agriculture. Urbanization, severe erosion, and the long history of forest clearing end up reaching the limit in the total quantity of arable land as well. And finally, the stable climate system upon which farmers, seeds, cultures and markets have adapted to is wobbly. Expectations are for extreme weather variance and a general decline in crop growth over time. These related forces I term "production-based food security." Overall, the quantity of food is threatened by depletion of resource stocks (fresh water, oil, natural gas, mineral fertilizers), degradation of soils, and climate change. Many would also add genetic diversity and aging farmers to this list.

These three classes of food security threats are not unrelated, of course. Rising energy costs impact the costs of production and distribution, which in turn lead to food inflation. But by framing security in these different ways, we can more clearly see the stresses in the food system and their underlying causes. All three classes of food security threats are occurring simultaneously, but at different rates and severity among different populations. Social movements have arisen in response, and their different emphases reflect the classes of threats summarized here. These movements also offer potential strategies to deal with each situation (See Table 1).

The problems of our food system are so deep and connected to so many other structures in our societies that only a multi-faceted approach that recognizes these relationships offers meaningful, long-term change. Fortunately, many are aware of this. Take for example the Community Food Security Coalition (http://www.foodsecurity.org/), which describes itself as:

The Community Food Security Coalition (CFSC) is a non-profit 501(c)(3), North American organization dedicated to building strong, sustainable, local and regional food systems that ensure access to affordable, nutritious, and culturally appropriate food for all people at all times. We seek to develop self-reliance among all communities in obtaining their food and to create a system of growing, manufacturing, processing, making available, and selling food that is regionally based and grounded in the principles of justice, democracy, and sustainability. CFSC has over 200 member organizations - join us!

The CFSC connects groups from across the spectra of social organizations throughout North America. I think it would be wise for each community to find their own set of players, from food banks to farmer's markets to community farms, and work together.

Imagine, for example, providing stable income to a local, organic community farm for growing food distributed to a school with many low income children? There, in one set of connections economic justice, decreased transportation, and sustainable agriculture strategies are integrated and reinforced. Who wouldn't be in favor of that?