Study challenges climate benefits of U.S. low-carbon fuels 

Source: Debra Kahn, E&E reporter • Posted: Wednesday, February 18, 2015

A recent study on the carbon footprint of biofuels is adding a new wrinkle to the already corrugated landscape of alternative fuels policies.

University of Michigan research professor John DeCicco wrote a study finding that the current method of calculating the carbon emissions associated with transportation fuels is essentially meaningless.

The model, known as “life-cycle analysis,” attempts to incorporate all emissions associated with the production and use of fuels, including those derived from petroleum, natural gas, hydrogen, electricity and plants. It was used in the development of U.S. EPA’s renewable fuels standard and California’s low-carbon fuels standard, each of which seeks to encourage the production of next-generation biofuels from plants other than corn, including soybeans, sugar cane and grasses.

But according to DeCicco, the model gives biofuels too much credit for taking emissions out of the atmosphere during the plant-growth stage.

“The big problem with the life-cycle models everyone’s been using is that they treat land, productive land, that’s removing CO2 from the atmosphere through plant growth, inconsistently when they do the analysis,” he said. “That’s the smoking gun, so to speak. That’s the deep error that everybody’s been missing when they do these analyses.”

DeCicco’s study faults the life-cycle analysis model for assuming that the land wasn’t previously in use, either to grow crops or to host native plants.

“You can’t create productive land from nowhere,” he said. “The corn that this year is being used for ethanol was last year going for food and feed. It’s not taking more carbon out of the air because it’s being used for ethanol than it was when the corn was being used for corn chips.”

Calif. and national fuel standards remain in flux

DeCicco predicts that when the models are redone, they will remove biofuels’ carbon advantage over fossil fuels. “When it’s corrected, it will essentially, from a carbon mitigation point of view, eliminate all biofuels currently in production and for the foreseeable future,” he said. He hasn’t done the calculations himself yet, he said, but is hoping to hire a postdoctoral student to work on the figures.

The study was published in the January-February issue of Wiley Interdisciplinary Reviews: Energy and Environment. It was funded primarily by the University of Michigan, with some support from the U.S. Department of Energy’s Clean Energy Research Center Clean Vehicle Consortium.

In an energy policy world where models are rapidly evolving and in flux, DeCicco’s work met with quick skepticism from advocates of current policies.

“The article is out of date, provides no useful alternative and fails to recognize the extensive scientific and stakeholder input, and independent peer review, that’s occurred over the past two years for the LCFS, resulting in greatly improved estimates that represent the best consensus of the current science,” California Air Resources Board spokesman Dave Clegern said. “Also, the LCFS [carbon intensity] calculations provide a framework where improvements in knowledge, data and models can be incorporated into improved estimates every few years.”

California’s fuel standard, which is intended to reduce the carbon content of transportation fuels 10 percent by 2020, has essentially been stalled due to a 2011 lawsuit from ethanol producer Poet LLC. The state’s air agency is due to consider proposed amendments Thursday at a hearing in Sacramento (ClimateWire, Jan. 5). Proposed changes include adjusted annual emissions targets through 2020, as well as updates to the carbon scores for various fuels, including palm-, soy- and canola-based biodiesel, as well as sugar-cane- and corn-based ethanol.

The federal renewable fuels standard has also been stalled, with U.S. EPA yet to issue new fuel production targets for 2014, 2015 or 2016 (E&ENews PM, Jan. 15).

Critics distrust ‘completely different accounting scheme’

An environmentalist who is active in renewable fuels policies said DeCicco’s study lacked practical implications.

“Academics very often come out and explain how policies policymakers come out with are inefficient,” said Jeremy Martin, a senior scientist in the Union of Concerned Scientists’ clean vehicles program. “Proposing a completely different accounting scheme that corresponds to a different universe of policy options doesn’t have much bearing on the world.”

A biofuels producer agreed.

“No methodology is perfect, but essentially throwing the baby out with the bathwater [and] not proposing how you do it differently is not quite helpful,” said Neil Koehler, CEO of Pacific Ethanol, which makes ethanol from corn, sorghum, beet sugar and waste material from wineries. “There is no way that we will achieve our climate goals without a significant amount of displacement of fossil fuels with biofuels.”

DeCicco worked for the Environmental Defense Fund in Washington, D.C., for eight years, and served as transportation director for the American Council for an Energy-Efficient Economy for 20 years. He said he knows that his work can be easily politicized.

“I know the work I’ve been doing the last few years is questioning a lot of long and deeply held assumptions about the value of renewable fuels,” DeCicco said. “I know some people are wondering because some of my positions sound like they’re in line with the oil industry’s.

“We’ve been arguing about this stuff already for over a decade,” he said. “These arguments don’t seem to be getting resolved; in fact, they seem to be getting worse.”