Corn used to produce ethanol will not help reduce out-of-control CO2 emissions
By James Curran
Published: May 8, 2008
There's no such thing as a free lunch, a lesson we are re-learning from the government-supported initiative that diverts corn from food crop to ethanol source (the Energy Independence and Security Act of 2007). The goals of the initiative are good. We need to reduce CO2 emissions and reduce dependence on foreign oil, and we must also increase mileage standards for our automotive fleet. But the ethanol mandate will have serious unintended consequences that are worse than the problems it was expected to solve. And the proposed increase of Corporate Average Fuel Economy (CAFÉ) standards to 35 mpg by 2020 is an exercise in underachievement.
The fundamental issue is that transportation requires energy-dense energy carriers. Hydrocarbon-based liquids are ideal, but the problems associated with burning fossil fuels are now well known.
Ethanol is almost as good an energy carrier, and it is attractive to use it as a supposedly renewable, domestic alternative. But recent studies indicate that the diversion of farmland to ethanol production, even cellulosic ethanol, will actually increase the atmospheric CO2 concentration for decades to come.
It's instructive to consider the magnitude of the problem. The U.S. transportation system uses about 500 million gallons of petroleum-based fuels every day. It would take our entire domestic corn production to replace that volume with ethanol. But because the world still has to eat, forests will be converted to cropland, which would release a tremendous amount of CO2 into the atmosphere, exacerbating one of the very problems that ethanol was supposed to alleviate.
Wide-scale use of farmland for cellulosic ethanol, while not quite as bad, would still increase atmospheric CO2.
So, where do we get domestically produced alternative fuels, preferably renewable, at reasonable costs? Only three biofuel strategies might make sense. One is converting wastes that are currently burned or buried into biodiesel or ethanol. Another is the use of agriculturally useless lands to produce grasses for cellulosic ethanol. Neither of those strategies will divert cropland, which is good; but they can produce only enough fuel to satisfy a portion of our needs. The third possible solution is the exploitation of oil-producing algae. Facilities for industrial-scale algal growth and oil extraction can be built with small footprints, and the ability of those tiny organisms to produce enormous yields in continuous-flow systems is truly amazing. The algal oil can then be inexpensively converted to biodiesel.
We might also ask, must our energy carriers be liquids? Given the option, I'll bet most would gladly trade a power cord for the gas pump. We demand that our vehicles travel hundreds of miles on a tank (or a charge) and then refill within a matter of minutes. Can such utility be achieved without liquids? We have long had electric motors capable of moving vehicles over a wide range of speeds for hundreds of thousands of miles. The limitation has been the inability to store enough power to make electric cars truly practical at competitive costs. But that limitation is rapidly disappearing. The high-tech industry has brought tremendous advances in battery technology, and progress continues at a very rapid pace. Batteries that can achieve the necessary milestones of high power density, short charging time and long duty life are on the near horizon. I can well imagine the day when instead of feeding parking meters, we will plug into "power poles" to recharge when we park. Of course, if electric cars are to cut CO2 emissions, then power companies will have to either use less fossil fuel or capture the CO2. This will also require at least 50 percent more power plants than we now have. These are difficult but solvable challenges.
Regardless of which transportation energy technology (or technologies) emerge, it is important that we begin developing alternatives as soon as possible. The Energy Independence and Security Act is well-intentioned, but its focus on biofuels is misguided. I suggest two revisions in the act.
First, turn loose American ingenuity by opening the initiative to all energy technologies that could potentially reduce CO2 emissions. This would include, but not be limited to, methods that could support transportation with electric vehicles. The development of competitive batteries and ancillary electrical components would also stimulate high-tech industries that could provide high-end jobs. Second, the act should do more to stimulate conservation. The mandated increase in CAFE standards is below what most other countries achieve now.
Clearly, the Energy Act was not well-thought. We must do better.
• James Curran is a professor of biology at Wake Forest University.
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