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Since We've Made Tortillas Expensive, Let's at Least Use Biofuels Wisely

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What the general public largely does not realize is that there are two separate yet related biofuels movements operating in the United States. The first is agribusiness: large scale biofuels production from giant companies like Cargill and ADM, with supporting cast members like Monsanto. Based entirely on industrial agriculture, using genetically modified corn and soybean crops, petrochemicals, and subsidies, this type of biofuel manufacturing seeks solely to maximize profits, no matter the external costs to biodiversity, clean air, or clean water. It is a hopeless endeavor. According to a report from the National Academy of Science, if all of our U.S. corn and soybean crop went to make biofuels, only 12% of the gas and 6% of the diesel fuel we consume could be supplied.


The second enterprise, represented under the umbrella of the Sustainable Biodiesel Alliance,
seeks to make biofuel (specifically, biodiesel) using regenerative farming practices, finding local feedstocks or tapping into waste streams, supporting local communities and limiting fossil fuel inputs to the minimum necessary. Sustainable biodiesel roots itself in social morality, which isn't to say the profit motive is nonexistent, but that as a priority profit has to get in line with environmentalism, community activism, sustainable farming, strong social networks, and the like. These folks know that there is no way we can sustain our current auto-centric lifestyle using biofuels. Instead, they want to supplant petroleum use in conjunction with a general reduction in our reliance on the automobile. They know that petroleum dependence is killing our planet, and forcing our nation to act against its core principles of independence and egalitarianism, and this is the problem they are trying to solve. They have worked tirelessly, oftentimes to the point of exhaustion, to promote a sustainable energy regime.

Unfortunately, the hard-won gains of this second honorable grassroots movement have been almost completely co-opted by the first. When we were in Des Moines, Iowa on our book tour
a few weeks ago, the environmentalists we were hanging out with were despairing of the fact that the covenants that had been agreed to with local farmers to not cultivate land adjacent to waterways were being abandoned. Farmers had been paid to leave these riparian areas fallow to help filter agricultural runoff before it seeps into the state's creeks and rivers. However, the skyrocketing price of corn for ethanol feedstock means that many farmers abandoned these agreements in order to grow more corn. They planted and fertilized, literally over what had once been streambeds in many cases ... and then this spring the rains came. And they kept coming. And all those petrochemicals spread all over their farm land went straight into the Mississippi. It was going to be the largest dead zone in the Gulf of Mexico ever, until Hurricane Dolly whipped by and spread all that nastiness over a larger area, meaning it only tied for second place.

We are deeply impressed with the sustainable biodiesel community in our home state of North Carolina. They are without doubt one of the most engaged, visionary, problem-solving, and socially active groups we know of. But the problem with biofuels on a larger scale is the same problem that afflicts other renewable energy sectors. And that is a monomania that treats energy scarcity, and only energy scarcity, as the one problem that needs to be solved.

When biomass is extracted from its environment and not returned, whether because it's shipped off to another land to be eaten, or burned in an engine stuck in traffic, the soil is depleted. On a small-scale level, this could potentially be rectified by nitrogen-fixing crops and other locally-procured nutrients. But when it happens on a larger scale, as with agribusiness biodiesel, the topsoil will eventually vanish. But even as a system of energy capture, biofuels will always be horribly, even preposterously, inefficient.

The typical car weighs 3,000 lbs and moves about 150 lbs of cargo, for a base efficiency rate of 5%. But the internal combustion engine is only about 15% efficient, so this 5% starting rate is then reduced down to around 1%. Photosynthesis is, on average, only about 2-3% efficient in converting sunlight into stored energy. Ultimately, biofuels burned in a private automobile don't just deplete our topsoil and kill our oceans, they are at most about .03% efficient at getting the job done. The private car is not now nor can it ever be globally sustainable, so any fuel for private car use purporting sustainability is a priori an oxymoron.

If we're truly interested in creating a sustainable transportation network, then we need to envision a future where our limited supply of biofuels (and supply will always be limited) is used for much more efficient modes of transportation such as public transit and car-sharing programs. By making these already green methods of transportation that much more sustainable, we can encourage further development as the numbers of environmentally aware users increase.

Of course, there are several biofueled options that use these same fuel resources much more efficiently and actually have the potential to increase topsoil and capture carbon dioxide in the process. They're called the human and the horse.

Stephen and Rebekah Hren are the authors of The Carbon-Free Home: 36 Remodeling Projects to Help Kick the Fossil-Fuel Habit from Chelsea Green. For more information about green living, the Hrens, or their book, visit

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