Policy Positions: Biofuels - a proven tool to combat climate change

In the past 30 years, the burning of fossil fuels, such as coal and oil, has caused the concentrations of greenhouse gases (GHGs) to increase significantly in our atmosphere. These gases prevent heat from escaping the atmosphere, somewhat like the glass panels of a greenhouse. As the concentrations of these gases continue to increase in the atmosphere, the Earth's temperature is climbing above historical levels, according to government data.

The primary GHG emitted by human activities in the United States is carbon dioxide, representing nearly 85 percent of total U.S. GHG emissions. Not surprisingly, the largest source of carbon dioxide is fossil fuel combustion. Americans used more than 142 billion gallons of gasoline in 2007, 16 percent more than was used 10 years ago and twice the amount used 40 years ago in 1967.

Fortunately, biofuels like ethanol are one of the best tools available today for combating the effects of greenhouse gas (GHG) emissions on the global climate. Because ethanol is made from renewable, plant-based feedstocks, the carbon dioxide released during a vehicle’s fuel combustion is “recycled” by the plant as it grows.

Numerous lifecycle analyses conducted by various government and university researchers have been performed on biofuels in the last decade. Most of these studies suggest today’s ethanol reduces direct GHG emissions by 25-40 percent compared to gasoline. These studies typically consider the total energy consumed in the fuel production process, the emissions of GHGs (including carbon dioxide, methane, and nitrous oxide), and emissions of criterion pollutants. According to the U.S. Department of Energy’s Argonne National Laboratory, “In terms of key energy and environmental benefits, Argonne’s GREET (model) shows that corn starch ethanol clearly outpaces petroleum-based fuels, and that tomorrow’s cellulose-based ethanol would do even better.” Indeed, Argonne analysis shows ethanol produced from cellulosic feedstocks promises to reduce GHGs by more than 80 percent compared to gasoline.

While future feedstocks and production methods are likely to magnify the GHG-reduction benefits of biofuels, ethanol is delivering results today. In 2008, it is estimated that the production and use of approximately 9 billion gallons of ethanol in the United States reduced carbon dioxide-equivalent GHG emissions by about 14 million tons. That’s the equivalent of removing the annual emissions generated by approximately 2 million cars driving on America’s roadways.

Low Carbon Fuels Standard

Because of its proven ability to reduce GHGs, ethanol will play a central role in emerging federal and state efforts to regulate fuels based on their global warming intensity. A “low carbon fuels standard,” such as the regulation under development in the state of California, is a public policy concept that requires incremental reductions in the carbon intensity and GHG emissions of the fuels we use. Under these types of policies, carbon intensity reductions can be achieved through a variety of means, but it is expected that blending high carbon intensity fuels (like gasoline) with low carbon fuels (such as ethanol) will be a primary method of achieving the goals of these policies.

In January 2010, the California Air Resources Board (CARB) implemented the California Low Carbon Fuels Standard (LCFS).  The goal of the LCFS is to reduce the carbon intensity of California transportation fuels by 10% by 2020. To earn credits under the LCFS, obligated parties will blend or replace high carbon intensity fuels with lower carbon intensity fuels. Because the LCFS is structured as a performance-based regulation, proper determination of a fuel’s lifecycle greenhouse gas (GHG) emissions is critically important. Under the LCFS, lifecycle analysis serves as the standard “measuring stick” against which the GHG emissions of all fuels are measured. However, CARB has unfortunately demonstrated an acute bias by using a different “measuring stick” for biofuels than for the other fuels covered under the regulation. CARB’s analysis of corn ethanol prematurely includes emissions from predicted indirect land use changes, while other fuels are immune to enforcement of penalties for any indirect impacts. As a result, CARB’s analysis suggests ethanol from corn is equivalent to gasoline in terms of lifecycle greenhouse gas emissions and therefore offers no GHG benefits. This finding stands in contrast to other recent analyses suggesting modern corn ethanol reduces GHGs 30-60% relative to gasoline (see Liska et al., 2009).