First it was spinach. Now it's green onions at the Taco Bell. What's next? The growing anxiety over our nation's food supply is enough to make you chew your nails -- unless of course they're contaminated with E. coli as well. Is nothing safe?

In the United States today, 80 percent of beef is slaughtered by four companies, 75 percent of pre-cut salad mixes are processed by two companies and 30 percent of milk is processed by just one company. Most of our fresh produce comes from the same region of California where the contaminated spinach and now green onions were grown. During off seasons, up to 70 percent of the produce sold in the United States comes from other countries.

Globalization has meant that, with the click of a button, we can connect with people and places halfway across the country or the world. But rather than just exchanging ideas and cultures, we've increasingly come to depend on the rest of the world for our consumption of goods, services, energy -- and food. With the speed of clicking a button, an E. coli outbreak in California or China can threaten our entire food supply and risk a widespread pandemic.

Gone are the days of family farms, which would produce sustainable, healthy food that also fed the local economy. Today, a staggering 330 farmers abandon farming each week. In the 1930s, there were over seven million family farms in our country. Today, roughly two million remain.

In their place, large, corporate-run farms have driven down the price of food, thanks largely to massive subsidies from the federal government but also "economies of scale." Yet we cutting costs comes at a price. When you buy an apple at your local farmer's market from a farmer's in your region, there's no packaging involved and the only energy the farmer spent to get you that apple was a few miles worth of gas.

When you buy an apple grown all the way across the country -- or on the other side of the globe -- that apple is wrapped in paper and cardboard and shipped over boats and planes and then trucks to your store, a considerably greater cost to the environment.

The money you spend on the apple, after the grocery store takes its cut, goes into the mega-profits of some distant agribusiness, a considerable cost to your local economy.

But also, aggregating farming means aggregating risk. In the case of the E. coli contaminated spinach outbreak this past September, the spinach was grown at massive, industrial farms in southern California and shipped around the United States.

The E. coli came from an industrial cattle ranch nearby. Tightly packed cows were over fed with unhealthy grain and produced E. coli in their feces. The contaminated feces washed downstream into the water supply, infecting the spinach fields.

There is much talk right now about "energy independence" -- the idea that the United States should rely on sustainable, renewable energy sources rather military conflict and political instability in the pursuit of oil. Food must be no different. Given the recent E. coli scares, we can no longer ignore the warning signs. Long-distance food of corporate agribusiness threatens our environment, our economy and our health. If we're feeling insecure, it's no wonder. We are what we eat.

There's a movement afoot to restore the health and safety of our food supply and support the livelihood and culture of small, family farmers. "The Meatrix", an incredibly clever animated spoof that exposes the dangers of factory farming, was viewed online by over 4.2 million people in the first three months it was released.

And just this past October, hundreds of thousands of people from over 150 continents convened in Turin, Italy, at a gathering for the international Slow Food organization, which calls for food that is good, clean and fair.

On it's website, the organization Local Harvest lists almost 10,000 farmers' markets, cooperative grocery stores, restaurants and more that provide locally-grown, organic produce to consumers. From Pulaski, Tennessee, to Moline, Illinois, there are already opportunities in big cities and small towns across the entire country to buy safe and nutritious food right from our own backyards. As demand for local produce grows, these markets will grow too.

Those of us who can afford to buy local, organic food grown sustainably by family farmers should do so. From jams and breads to apples and nuts, if we lead with our taste buds and our wallets we will over time help bring down the cost of locally grown food by eliminating the unfair competition of subsidized, artificially cheap agribusiness.

We will also solve the food crisis worldwide, where U.S. agribusiness has similarly trampled family farms and local food production from Mexico to India. Our reward will be a better world -- and food on our table that is nutritious, delicious and safe to eat.

Sally Kohn is the director of the Movement Vision Project of the Center for Community Change, which is interviewing hundreds of activists across the country to determine the progressive vision for the future of the United States.