Biofuels—fossil fuel replacements made from plants—are touted as a significant part of the solution to North America’s long-term energy needs. And as we’ve all heard by now, the favored gasoline substitute is ethanol made from corn.
The U.S. government has responded in kind, fostering the development of biofuel technology and subsidizing corn and ethanol production. Meanwhile, ethanol producers have widely published claims (do a quick Internet search and you’ll find them) to convince America that ethanol is a viable, large-scale, environmentally friendly energy source.
But data from peer-reviewed, independent research doesn’t jive. To the contrary, many in the scientific community have found the fuel to be inefficient, impractical in the face of our energy needs and ecologically irresponsible. And because ethanol production requires so much water from cornfield to tank, our precious fisheries are poised to bear the brunt of its environmental onslaught.
Ethanol Is An Energy Drain
The U.S. Department of Agriculture reports that corn ethanol produces a net energy gain of 25 percent. In other words, it takes the energy equivalent of four gallons of gasoline to produce five gallons of fuel-grade ethanol.
Heat energy is needed for the fermentation process and to distill the ethanol to 95 percent purity. Although that energy comes from various sources, some of it ultimately comes from fossil fuels. And corn needs a lot of nitrogen fertilizer (made with natural gas) and pesticides (derived from petroleum).
Those numbers aren’t very encouraging, but many believe them to be much worse. Studies by the U.S. Department of Energy published in the 1980s, for example, actually reported a negative energy return for ethanol.1,2 In other words, the research showed it took more energy to produce ethanol than the energy that fuel ultimately yielded. These studies were reviewed and accepted by a team of 26 expert, independent scientists.3
Numerous recent studies concur. When all energy inputs from planting corn to finished ethanol are considered, professors emeritus David Pimentel of Cornell and Tad Patzek of the University of California-Berkley determined that producing a gallon of corn ethanol requires 29 percent more fossil fuel energy than is contained in the finished ethanol.
So Many Cars, So Little Land Americans burned 134 billion gallons of gasoline in 2003. It would take more than 546 million acres of farmland growing corn to produce the volume of ethanol to replace the gasoline we used that year. Looking at substituting corn ethanol for gasoline globally, scientists forecast that 80 percent of the Earth’s total land area would need to be producing fuel crops.4
But that’s just not in the cards—globally, 37 percent of all land, and almost all good-quality land, is already farmed. Meeting global petroleum needs with corn ethanol will require farming marginal farmland, deserts and Siberia, and replacing forests with row crops.
And non-farmed lands have, since the development of agriculture, supported the bulk of Earth’s wild plant and animal species. “Set-aside” programs, such as the Conser-vation Reserve Program (CRP), provide incentives to plant marginal farmland or land with highly erodible soils with native grasses, shrubs and trees that protect the soil while providing essential habitat for many terrestrial wildlife species. These islands of wildlife habitat in a sea of row-crop monocultures provide vital refuges to sustain biodiversity and maintain game and non-game wildlife populations.
Increased subsidies to grow corn and develop corn ethanol technology is seen as a serious blow to wildlife by game managers and conservationists. They are concerned that CRP lands will be converted to corn production, which some parts of the country have already seen on a huge scale. The change is not only bad for terrestrial wildlife, but it will also accelerate erosion, thus adversely affecting fisheries resources.
Ethanol Is Not Clean Fuel I’m not sure where the public has gotten the idea that ethanol is “green.” Admittedly, alcohol burns mostly to carbon dioxide and water, whereas burned gasoline produces complex hydrocarbons and particulates. But that minor difference does not make burning ethanol good for the environment, because carbon dioxide is still a greenhouse gas and major contributor to global climate change.
True, when we burn ethanol, we are essentially recycling carbon dioxide rather than releasing it, as we do with fossil fuels. The corn plant converts carbon dioxide to corn, which is then processed to fuel, which is then burned, returning the carbon dioxide to the atmosphere and completing the cycle.
That said, using corn alcohol as a petroleum substitute appears to approximate a balance between carbon dioxide uptake by plants and carbon dioxide produced when ethanol fuels are burned—but that’s only if you don’t count fossil fuels used to grow corn and produce ethanol.
Some proponents of E85 go a step further to proclaim the increase in planted acres will mean more plants consuming carbon dioxide and, thus, a net removal of carbon dioxide from the environment.
Fast forward a few years, however, and you’ll see the flaw in this claim. As the need for corn ethanol increases (and it will), forests, wetlands and prairies in long-term conservation easements will be phased into corn. These areas are currently cleansing the atmosphere of carbon dioxide throughout a long growing season, but they’ll be replaced by corn that only grows—and removes carbon dioxide from the air—for about four months.
And while ethanol may burn cleaner than petroleum fuels, the path from farm to finished product is dirty. Corn production causes more soil erosion and demands more herbicide and insecticide use than any other U.S. crop.
Ultimately, much of those herbicides and insecticides end up in our surface or ground waters.
Impacts On Fish The ethanol boom poses numerous problems for inland fisheries, but the greatest threat is the tremendous water requirements—both of corn and the ethanol production itself. Corn requires more water than most crops. In Nebraska, it requires about 30 inches of water per growing season, more in hotter, drier climates and less in cooler, more humid climates. So until a few years ago, farmers grew corn where rainfall was adequate or irrigation water was cheap and readily available. Now that the incentive to grow corn is higher than ever, farmers are expanding corn acreage into marginal agricultural land, and that means more irrigation.
Water for irrigation can only come from three sources: diverted river flows, water-supply reservoirs, and aquifers (groundwater). Growing corn where it traditionally hasn’t been farmed because of insufficient precipitation will sap both surface and ground waters. And providing the power to physically pump this water will place additional demands on an already overdrawn energy budget.
But the water needs of ethanol don’t end with just irrigating corn crops. Once the crop is harvested it must be mixed with water for fermentation into alcohol. This process requires about 15 gallons of water to produce one gallon of 95 percent ethanol (13 of which are returned to the environment as sewage effluent).3
Producing enough ethanol to satisfy our 2003 gasoline consumption rate will require 1.7 trillion gallons of water and discharge almost 1.5 trillion gallons of wastewater. That water demand is 5.2 million acre-feet, the equivalent of a 260,000-acre lake with an average depth of 20 feet. The wastewater would fill up a 230,000-acre hole 20 feet deep.
Not all water for making ethanol will come from reservoirs. Some will come from rivers and aquifers. Water withdrawal can be sufficient to alter river flows and will be especially disastrous during dry seasons and droughts. Pumping ground water will lower the aquifers, which in turn will mean less flow in spring-fed streams and less base flow in many streams and rivers. The cumulative result: adverse effects on stream fishes.
Expanded corn farming also means deteriorating water quality. This is a double-edged sword. First, more tilled land means more erosion, more nutrients and more chemical pesticides. Corn requires a lot of nitrate fertilizer. It is a no-brainer that nitrate fertilization will increase as the price of corn goes up and more acres are planted. The nitrate ends up in rivers and lakes where it contributes to algae blooms and water-quality problems.
But it doesn’t stop there. Almost all corn is grown in the Mississippi River basin, which includes the Missouri and Ohio rivers and their tributaries. The nitrate-laden water flows to the Gulf of Mexico where it causes algae blooms that lead to low oxygen and massive fish kills off the Louisiana and Texas coast. In 2008, the “Dead Zone” was 8,500 square miles, an area almost as large as Lake Erie.
The other edge of the sword? Part of the increased acreage tilled will come from lands that presently form vital riparian buffers that filter sediments, nutrients, and pesticides from runoff heading to lakes and streams. As more land is farmed, less land will be available to remediate the problems caused by farming, exacerbating problems like the Dead Zone.
I think it is reasonable to expect the net energy equation for producing ethanol to improve. Genetic engineering is moving forward at warp speed and may lead to corn or another crop that has a higher and more efficient fuel yield, a lower water requirement, and possibly greater disease resistance. Ducks Unlimited, for example, is building legislative support for intensifying research on the use of native grassland plants for biofuel.
More efficient farming practices and equipment may reduce energy, water and nutrient use. Improved fermentation and distillation processes are also possible. Responsible decisions about our energy needs must be made within the bigger picture of the carbon cycle. And that means decisions must be made globally.
Climate change is real. That in itself will affect energy demands. But it will also affect precipitation patterns, which in turn will affect agriculture. What effect might a one-year drought have on the availability of E85 when 85 percent of what you pump into the tank comes from corn, or any plant for that matter?
That said, any energy solution must ensure a zero net gain of carbon dioxide in our atmosphere with a goal of reducing carbon dioxide. The latter can only be achieved by alternative power sources—like solar, wind and nuclear energy—and by reduced energy consumption.
But these changes will only be effective if we live on a planet with abundant plant life to sequester the carbon that we have steadily added to our atmosphere.
Stay informed about ethanol and other energy sources, and carefully scrutinize that information. This will be especially difficult because the issue has become highly polarized with each side trying to sway the public. Look for facts supported by numbers; don’t blindly accept claims.
Because although I don’t know what future energy solutions will be, I guarantee they could profoundly affect our aquatic resources.
Put It In
How much land does it take to keep on truckin’ and fishing with ethanol-based E85 fuel?
Last year, I drove about 6,000 miles to work and 14,000 on fishing trips pulling my 20-foot Ranger. My pickup gets 17 mpg commuting, but that drops to about 13 when trailering. In round numbers, I burned 350 gallons commuting and almost 1,100 gallons on fishing trips. I also burned 560 gallons of boat fuel. Total vehicle and fishing gasoline: 2,010 gallons.
Using U.S. Department of Agriculture statistics, one acre of corn yields 314 gallons of ethanol. But before you start calculating, consider this very important fact: Ethanol has less energy than gasoline—about 35 percent less.4
Therefore, my commuting mileage would drop to 11. Let’s assume the 35 percent reduction in fuel mileage also applies to trailering and boat travel. Taking those factors into consideration, I would have required 3,092 gallons of E85 (85 percent ethanol and 15 percent gasoline), which contains 2,628 gallons of ethanol, to commute, pull my boat and run it on the water (assuming engineers figure out how to make outboards that run on E85).
Now it’s simple: 2,628 gallons of ethanol divided by 314 gallons of ethanol per acre of corn equals 7 acres. We could feed a lot of people from the crops produced on 7 acres of farmland. Indeed, it takes 1.2 acres of cropland to feed an American.3 And making that much ethanol will consume more than 39,000 gallons of water and produce 34,164 gallons of wastewater.
Just traveling back and forth to work (458 gallons of ethanol) makes me alone an economic and environmental disaster.