It's important to understand the many interconnections between the food and energy sectors in order to make good consumer choices and develop prudent public policy. A recent Scientific American article by Michael E. Webber makes a big contribution to this effort by examining the food system through the "lens of energy use." Webber explains that looking at the food supply in this context "reveals opportunities for smart policies, innovative technologies and new dietary choices that can potentially solve food and energy problems together. The same steps would also make our bodies, and our ecosystems, healthier."
So how much energy is required to grow food? According to Webber, about 10 percent of the U.S. energy budget is associated with "producing, distributing, processing, preparing and preserving the plant and animal matter we consume." And what's the rate of return on that investment of energy? Unfortunately, it's not very good. "The energy used to make food is vastly greater than the amount of energy we get out of it," writes Webber. In the United States, it takes about 10 units of fossil energy to produce one unit of food energy.
This ratio is not sustainable! Americans need to find ways to reduce it if there's any hope of decreasing our own food-energy consumption, and so does the rest of the world, especially as the population is projected to top nine billion by 2050.
So how can we nibble away at that harsh ratio?
In a statement that is bound to generate much discussion, Webber suggests that what we at GRACE -- and many others -- have promoted as a solution to some of the many social and ecological problems associated with our food system -- i.e. eating local -- may in fact be inefficient when compared to large-scale industrialized agriculture.
[M]any people have latched onto the local-food movement, billing themselves "locavores," as an antidote to the energy used to transport food long distances and the energy intensity of large-scale industrialized agriculture... Strangely enough, shipping food thousands of miles can sometimes require less energy, emit less carbon dioxide and do less environmental damage.
Webber's article is primarily looking at the food system from the energy standpoint. Of course there are many ways to look at this issue; there's much to be said about the negative externalities associated with industrial agriculture because, as he notes, food production "exacerbate[s] global warming, river and ocean pollution, and a host of other ills." When talking about the food system, GRACE believes it is imperative to keep in mind these "other ills" while examining this system through the energy lens (or for that matter, the energy system through the water lens). The efficiency of industrial agriculture is a topic that Ecocentric has covered. In my colleague Chris Hunt's post, he explains:
Industrial foods benefit from certain efficiencies afforded by the highly developed nature of Big Ag's distribution networks... But there's no reason that local distribution networks can't be rebuilt to improve transportation efficiency... In any case, efficient distribution networks for non-industrial foods won't be reestablished if local farmers don't have consumer support in the interim -- purchasing locally produced foods is a good way to provide this support to ensure that local networks will be improved.
We may not be in agreement with Webber when he compares the established (oh, and highly-subsidized) industrial agriculture with the growing but still small movement of local farmers, but we are on the same page with him when it comes to the issue of food waste. Reducing food waste is another opportunity for consumers to make a difference, a point that Webber raises later in his article. He explains:
An egregious 25 percent or more of the food grown is wasted annually. That massive amount represents 2.5 percent of annual U.S. energy consumption -- more energy than all the ethanol produced in 2011 in the U.S. and more than the energy that will be produced in 2030 from lifting drilling restrictions today on the outer continental shelf. Simply decreasing the amount of food we throw away might reduce energy consumption and greenhouse gas emissions more over the next decade or two than many of the expensive or controversial energy supply policies that have been proposed. [Emphasis ours]
Webber, in his article, also provides some excellent insights into innovative farming techniques like drip irrigation, which yields "more crop per drop" and in the process, conserves water and the energy required to pump it.
The conventional approach -- the center-pivot sprinklers that create alienlike green crop circles in the middle of brown deserts (easily visible when flying overhead) -- is extremely wasteful, spraying water into the air where a major fraction evaporates... In a typical drip-irrigation setup, long sections of narrow tubing laid at the bottom of plants sown in a row deliver water directly to the roots. Researchers at Iowa State University estimate that corn farmers in that state would use 40 percent less water and lower their energy bills by 15 percent with drip irrigation.
Making the food system more energy-efficient won't be easy, but with smarter consumer choices, innovative techniques and more sensible policies we can easily get our food-to-energy ratio down to, say, five-to-one.