November 16, 2012

Biofuels That Cause Land-Use Change May Have Much Larger Non-GHG Air Quality Emissions than Fossil Fuels

Time

1:30 p.m. – 3:00 p.m

Location

1065 Kemper Hall

Speaker(s)

Dr. Elliot Campbell, Assistant Professor, UC Merced

Abstract

Although biofuels present an opportunity for renewable energy production, significant land-use change resulting from biofuels production may contribute to negative environmental, economic and social impacts. Here we examined the non-GHG air pollution impacts from both indirect and direct land-use change caused by the anticipated expansion of Brazilian biofuels production. We synthesized information on fuel loading, combustion completeness, and emission factors, and developed a spatially explicit approach with uncertainty and sensitivity analyses to estimate air pollution estimation emissions. The land-use change emissions, ranging from 6.7 to 26.4 Tg PM2.5, were dominated by the deforestation burning practices associated with indirect land-use change. Except highly uncertain LUC forecasts, the largest uncertainty in LUC emissions estimation in this study is from the combustion completeness for deforestation (ranging from 65% to 132% of baseline estimates). We also found Brazilian biofuels including sugarcane ethanol and soybean biodiesel including direct and indirect land-use change effects with land-use change effects have much larger life-cycle emissions than conventional fossil fuels for all six regulated air pollutants.

While the emissions magnitude and uncertainty both decrease with longer life-cycle integration periods, results are conditional to the single LUC scenario employed here due to inherent uncertainty in LUC projections. After LUC temporal projections uncertainty, the largest source of uncertainty in net LUC emissions stems from the combustion completeness during deforestation (ranging from 65% to 132% of baseline estimates). However, the results are conditional to the LUC data due to the high uncertainty of LUC forecast. While current biofuels cropland burning policies in Brazil may seek to have positive impacts on air pollution life-cycle emissions reductions, these policies do not address the much larger emissions caused by indirect land-use change.

Biographical Sketch

Biographical sketch: Elliott Campbell’s research interests are focused on understanding land-
atmosphere fluxes at large-scales with applications to the carbon cycle, climate feedbacks, and
biofuels sustainability.

Campbell received the NSF/CAREER award and has provided scientific consultations on state,
federal, and international policy. His work has appeared in media ranging from NPR’s “Morning
Edition” to The Economist. He received his BS and MS from Stanford, PhD from the University of
Iowa, and completed a postdoc at the Carnegie Institution for Science. He is currently an assistant
professor in the School of Engineering at the University of California, Merced with an appointment
to the Sierra Nevada Research Institute.