At some point in the future, humanity will have to produce its food without the help of fossil fuels and without destroying the soil. In a well-researched and succinct new essay, “What will we eat as the oil runs out?“, Richard Heinberg analyzes the main problems with the global agricultural system, and proposes a solution: a global organic food system.

Heinberg lays out four major dilemmas of the current system:

The direct impacts on agriculture of higher oil prices: increased costs for tractor fuel, agricultural chemicals, and the transport of farm inputs and outputs … the increased demand for biofuels … the impacts of climate change and extreme weather events caused by fuel-based greenhouse gas emissions…[and] the degradation or loss of basic natural resources (principally, topsoil and fresh water supplies) as a result of high rates, and unsustainable methods, of production stimulated by decades of cheap energy.

He then goes into more detail concerning these four horsemen of the agricultural apocalypse, and shows how, even now, these crises are leading to a decrease in global food production.

Later in this post I will propose a thought experiment solution, based on Heinberg’s solution of a fossil fuel-free agriculture:

The idea is not new. The aim of substantially or entirely removing fossil fuels from agriculture is implicit in organic farming in all its various forms and permutations – including ecological agriculture, Biodynamics, Permaculture, Biointensive farming, and Natural Farming. All also have in common a prescription for the reduction or elimination of tillage, and the reduction or elimination of reliance on mechanized farm equipment. Nearly all of these systems rely on increased amounts of human labor, and on greater application of place-specific knowledge of soils, microorganisms, weather, water, and interactions between plants, animals, and humans.

In order to make the agricultural system fossil fuel-free, the transportation of food will have to be minimized; in other words, agriculture will need to be relocalized. Let’s look at the United States; could organic, local farming feed everybody? I thought that as a first approximation of an answer to this problem, I would make a set of very simplified assumptions:

First, assume that 80 percent of the population lives in a city the size of New York City. New York City covers 786 square kilometers of land (300 square miles), and contains 8.2 million people. Thirty New York Cities would hold 246 million people, and cover only 3/10 of 1 percent of the 7,900,000 square kilometers of the lower 48 states! (All data from wikipedia.) Of course, there would be no suburbs … but as I said, this is a first approximation.

Assumption number two: all farming acreage would exist in a belt around each “New York City.” And how much land would this require? According to John Jeavons, inventor of the Biointensive farming system, the average American currently needs at least 15,000 square feet for food production. Jeavons claims that a vegetarian diet with vegetable sources of protein can be produced for one person using biointensive techniques on 4,000 square feet. Let’s assume, however, that we will add an extra 2,000 square feet to allow for some fish and to raise some chickens, and that we will even make room for red meat lovers by letting the prairie reassert itself and culling a certain sustainable percentage from the millions of bison that again roam the plains.

So we can envision each NYC-type city being surrounded by 8 million times 6,000 square feet, or 48 billion square feet of farmland, or 1,722 square miles, in other words: about 6 times the area of the 300 square miles of the city. So only about 2 percent of the land area of the continental U.S., theoretically, could feed and house the American population.

The third assumption of my primitive model is that the remaining 20 percent of the population could produce all the food grown in the farming belts around each city. In another essay, Heinberg estimated that a farming population of about 50 million people might be necessary in a fossil fuel-free future; 20 percent of 300 million is 60 million people.

Of course, we could loosen these assumptions to make room for cities and towns that were smaller than New York City (not that I wouldn’t mind, but I think many others would). Or think of it this way; perhaps this thought experiment can serve as a small effort to fulfill one of Heinberg’s suggestions:

1. The various strands of the organic movement must come together so that they can speak to national and international policy makers with a unified voice.

2. The leaders of this newly unified organic movement must produce a coherent plan for a global transition to a post-fossil-fuel food system.

Any suggestions?