The farm fields are again sprouting with their recently planted corn and soybeans, and those verdant fields, once reserved for growing food, are increasingly devoted to what people are now calling renewable fuels. Those fuels, ethanol from corn and biodiesel from soybean oil, are touted as the path to energy independence and clean air and as an answer to global warming. How innocuous and wholesome these fuels must seem: They come from things we eat; the smell of biodiesel is no more offensive than that of french fry oil; ethanol is nothing more than the same alcohol we find in all alcoholic drinks; and the carbon dioxide which both fuels release into the atmosphere gets reabsorbed by the following year's planting.
That, anyway, is the extent of the story one might get from recent coverage of the biofuels boom. But are these fuels really the renewable wonders they seem? That may hinge on what people mean by renewable. If they mean that for a limited time the crops from which liquid biofuels are made can be repeatedly grown, harvested and processed to make biofuels, then they are perhaps in a very narrow sense correct. If what they mean by renewable is sustainable, then they are just plain wrong. Biofuels produced the way we are producing them today are not even close to sustainable. In truth, the current production methods for biofuels are more like mining operations than farming operations. That calls into question whether such fuels can deliver the benefits which are now being so incessantly trumpeted in the news media.
To understand why this is so, we have to go beyond the fleeting glimpses of farm fields that we get from our cars--glimpses that for many of us form the sum total of our knowledge of farming. If one were to stand across from a field of corn or soybeans for an entire season, one would, in most cases, witness the following: plowing done with a tractor, planting using large mechanical planters, the spraying of herbicides and pesticides, the application of fertilizers, irrigation (in some cases), and harvesting done by large machinery. In fact, one would see that all of the heavy field work is done by petroleum-powered machines.
This style of industrial farming involves huge petroleum and natural gas inputs to fuel the machinery; to make and apply the herbicides, pesticides and fertilizers; and to irrigate and harvest the crops. Many people don't know that oil is the basis for most herbicides and pesticides and that natural gas is the basis for most of the world's nitrogen fertilizers. (Nitrogen fertilizers are used heavily on corn, but not on soybeans which produce their own nitrogen.) Both oil and natural gas are finite resources; their use to help grow crops for fuel can in no way be called sustainable. In effect, we are mining finite hydrocarbons to grow crops for biofuels.
In addition, industrial farming causes soil erosion on a horrific scale. A recent study shows that soil in the United States is eroding at a rate that is 10 times faster than the rate at which it is being replenished. The numbers are worse in places such as India and China where the erosion rates are 30 to 40 times faster than the rate of replenishment. And, while many areas of the United States get ample rainfall, others require irrigation to be productive. That leads to another problem: overpumping. David Pimentel, one of the world's leading researchers on biofuels, pointed out in a recent study that "[i]n some Western U. S. irrigated corn acreage, for instance, in some regions of Arizona, groundwater is being pumped 10 times faster than the natural recharge of aquifers." This can hardly be termed a sustainable practice.
But, even where there is plenty of water to pump, irrigation can cause salt to build up in the soil rendering it useless for crops. In all, close to 50 million acres of farmland worldwide are lost to soil erosion and salinity each year. In effect, we are mining the soil and the acquifers of the world to produce crops.
But, we have yet to discuss the processing of crops for liquid biofuels. Here, the news is no better. First, of course, there is the diesel or gasoline burned to transport crops from the fields and grain elevators to the production facilities. More fuel is burned to transport the finished fuels from the production facilities to the service stations. The production facilities themselves run on a combination of electricity, natural gas and/or coal. In fact, the high price of natural gas has led ethanol producers to build new plants that will use coal for energy and heat. Electricity isn't exactly clean, either. It has to come from a generating plant that almost always uses either coal, natural gas or uranium to produce it. What this means is that the reputation that ethanol and biodiesel have for being "clean fuels" is rapidly being tarnished. The extensive use of fossil fuel energy to produce liquid biofuels can in no way be construed as renewable. Again, we are simply mining finite resources to run the production facilities.
The obvious question for newcomers to the biofuels debate is why biofuels themselves aren't used to run the production plants. The answer is troublingly simple: Under present methods of agriculture and processing, liquid biofuels are energy losers. Their production uses more energy in the form of fossil fuels than the finished biofuels contain. In fact, the entire biofuel regime is not only unsustainable, but a huge boondoggle which only exists because of large government subsidies. Absent those subsidies, no one would make liquid biofuels in commercial quantities.
Perhaps, you say, technology will improve, and we will eventually get more energy from biofuels than we expend to make them. No one can predict the future. But it is worth keeping in mind that the energy profit ratio--the amount of energy we get back from petroleum, natural gas and coal for each unit we expend extracting, processing and transporting them--ranges from 10 to 1 to 20 to 1. Biofuels are currently below 1 to 1 in their return. In other words, they are energy negative. Even if their energy profit ratio were to improve to say, 2 to 1 or 3 to 1, we would still find ourselves living in a very low-energy world if we had to rely on biofuels alone.
But, it is doubtful that, even in this best-case scenario, biofuels would do very much to help us. First, there isn't enough arable land to make much of a dent in the liquid fuels market. Perhaps even more important, food and fuel are already beginning to compete with one another and that has serious implications for most of the world's population which is poor. Some 3.7 billion people are currently considered malnourished. The last thing they need is higher food prices.
So, next time you pass by those fields of corn and soy, think of what you don't see; think of the hidden life of biofuels. Don't get bamboozled by the cynical public relations ploys of the biofuels producers; their only goal, after all, is to get you to support their lucrative subsidies. And, don't get taken in either by the wishful thinking of well-intentioned biofuels advocates; unfortunately, some may lead you to believe that life in the future will look pretty much like life in the recent past if we commit to biofuels.
Liquid biofuels are not renewable under any reasonable definition that also means sustainable. And, far from helping us kick our fossil fuel habit, the production of biofuels is only making our addiction worse.
(This article was based in part on papers published by David Pimentel and Tad Patzek. If you would like copies of those papers, email Kurt Cobb at firstname.lastname@example.org.)