Debate Over Biofuels’ Carbon Footprint Heats Up

Posted by Jared Killeen on October 29, 2009 at 10:58 am

Are biofuels a low-emissions solution to the country's energy issues...(image: alternative-energy-one.blogspot.com/)

It has become a widely held belief, if not a dictum of environmental gospel, that biofuels are the future of a clean, energy-efficient America. After all, some leading climate scientists have argued that burning ethanol or switch grass produces no carbon emissions—and what’s greener than that? When compared to fossil fuels like coal and oil, biofuels look squeaky clean.

Before you decide to buy an ethanol-powered car, remember it’s not that biofuels produce no emissions at all—it’s that they produce no new emissions. According to this clever theory, expounded by biofuel promoters like the Renewable Fuels Association (RFA), the carbon dioxide released during the combustion of biofuel existed all along. In fact, it was originally removed from the atmosphere by the corn or grass in question, and is merely re-released when the plants are burned. Thus, biofuels don’t add carbon dioxide to the air, they simply put it back. As Brent Erickson, executive president of the Biotechnology Industry Organization (BIO), recently put it: “Biofuels and biomass energy recycle atmospheric carbon, while fossil energy takes carbon that has been stored for millions of years in the earth and releases it into the atmosphere.”

To some critics—among them the Environmental Protection Agency (EPA)—this theory is flawed. In fact, a recent article in Science, penned by a number of concerned scientists, goes so far as to suggest that biofuels might actually cause greater damage to the environment than fossil fuels by leading to more greenhouse emissions. The article claims that current analyses of biofuels “have failed to count carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels.” That is, as more land in the United States is diverted to biofuel production, land in other countries will be turned into farmland to make up for lost production, leading to unchecked deforestation and increased CO2 emissions.

...or will the demand for biofuel crops just cause more deforestation and increase global warming emissions? (image: izzatirahim.blogspot.com)

This unfortunate side effect of biofuels—often tacked onto environmental declarations as a sort of subordinate clause—is the product of what is called ‘indirect land use.’ Whether or not it should be included in calculations concerning the potential emissions of biofuels is a matter of great debate. In its proposed Renewable Fuel Standard program (or RFS2), the EPA has recommended that indirect land use be considered when calculating the environmental effects of biofuel production. Thus, although it is commonly held that biofuels might help reduce greenhouse gas emissions by 60 percent, a consideration of indirect land use reduces the benefit of biofuels over fossil fuels to a mere 16 percent. Even more alarming are the findings published in the aforementioned Science article: “By using a worldwide agricultural model to estimate emissions from land-use change, we found that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years.” Suddenly biofuels don’t seem so squeaky clean.

One contributor to the Science article, Tim Searchinger of Princeton University, recently told NPR that ignoring emissions released by indirect land use is equivalent to bad logic. Miming the argument of biofuel advocates, Searchinger quipped, “Even if you were to cut down the world’s forests and turn them into a parking lot, and take the wood and put it in a boiler—which obviously releases enormous amounts of carbon from the trees—that is treated as a pure way of reducing greenhouse gas emissions.” Searchinger then added, “And that’s obviously an error.”

This so-called error has already found its way into much European environmental law, as well as the Kyoto climate treaty. “The problem is that when the world agreed to a treaty that limited the amount of carbon that goes up the smokestack, they didn’t agree to limit the amount of carbon released by cutting down trees,” Searchinger said. It is no small irony, according to Searchinger and other scientists, that by trying to avoid counting carbon emissions twice, treaty negotiators ended up with a system that doesn’t count them at all. According to Searchinger, “The fundamental effect of this [error] is to make forests worth more dead than alive.” That is, countries looking to reduce their carbon emissions now have incentive to cut down forests, burn up the timber, and replant the area with biofuel crops. How to correct the error? Count international emissions caused by indirect land use against US biofuel production.

Those close to the biofuel industry have rejected Searchinger’s claims, as well as his suggestion that indirect land use emissions be considered by policy makers. Brent Erickson and BIO have argued that the EPA’s proposed policies “distort [the] simple fact” that biofuels “recycle” carbon dioxide, and that “well-managed biomass production can sequester more carbon in the soil than is released into the atmosphere through combustion of biofuels and bioenergy.” According Novozymes, a biotechnology company, the EPA has failed to note the existence of new land use techniques based on carbon soil sequestration, in which biomass is not burned, but instead turned into biochar via pyrolysis. The nano-porous char is then stored in the soil to form a stable carbon sink. The result is highly fertile soil that boosts crop yields, reduces the need for fertilizer, and offsets the carbon debt from the first operation.

Like Erickson and BIO, Bob Dinneen, CEO and president of the RFA, has complained that the “unproven theory” of indirect land use will only punish the renewable energy industry and frustrate efforts to promote biofuels as an alternative to petroleum-based fuels. Thus, Dinneen hopes to suggest that the EPA is also guilty of “bad logic”: by including considerations of indirect land use in the RFS2, the EPA is effectively stonewalling biofuel development, and thereby defeating its own attempt to protect the environment and promote cleaner fuels.

If it seems like both sides have made convincing arguments, it’s probably because they have. It is tempting to view Dinneen and Erickson as cheerfully ferocious underdogs, championing a small industry bullied by big government. (What makes biofuel especially appealing is that, according to Dinneen, it may keep oil prices down.) Likewise, it is heartening to think that the EPA and Science have the environment’s best interests in mind and that they are not simply protecting Big Oil. Of course, organizations like the RFA and BIO, and companies like Novozymes, are deeply invested in the biofuel industry, and are thus likely to lobby for biofuel-friendly policy no matter what. The only certainty is that the debate over biofuels has just begun, and that along with more scientific research on the effects of land use change, we are likely to see a great deal of public lobbying from both sides.