Cooperative Institute for Research in Environmental Sciences

Air Pollution Effects of and a Renewable-Energy Solution to Global Warming

Mark Z. Jacobson

Dept. of Civil and Environmental Engineering,
Stanford University

Abstract
In order to stabilize climate while accounting for future economic growth, it is necessary to reduce current emissions of anthropogenic greenhouse gases and particulate black carbon by 80% during the next 20 years. Because outdoor air pollution is a major cause of death, cardiovascular disease, and asthma, any solution to climate change should also improve air quality, particularly since air pollution-related mortality is calculated to increase as the climate warms further. Here, I compare potential vehicular solutions to global warming and air quality, including ethanol-fueled (corn or cellulosic) vehicles, wind- or solar-powered battery electric vehicles, and hydrogen fuel cell vehicles. Ethanol-fueled vehicles were found not to improve and possibly worsen air quality relative to gasoline, which is already a significant health hazard. Hydrogen fuel cell vehicles were found to improve air quality significantly compared with gasoline, regardless of the production method of hydrogen, but with production by wind electrolysis being the cleanest. Wind-powered battery-electric vehicles were as clean as wind-powered hydrogen fuel cell vehicles, but about three times more efficient. Wind-powered battery vehicles required 30 times less land area than corn ethanol and 20 times less land area than cellulosic ethanol for powering the same vehicle fleet. In the best scenario, corn ethanol cannot reduce U.S. carbon by more than 0.2% and cellulosic ethanol cannot reduce U.S. carbon by more than 4% due to their carbon emissions and landuse constraints. Evaluation of the world's wind resources suggest that sufficient wind exists worldwide over land for climate and air pollution problems from vehicles and power plants to be addressed by wind power many times over. It is shown that the combination of wind, solar, hydroelectric, and geothermal power together can be used to supply baseload or load-matching electric power, particularly in combination with electric vehicles in a smart electric grid.

About the Lecturer
Jacobson is Director of the Atmosphere/Energy Program and Professor of Civil and Environmental Engineering at Stanford University. He is also Professor of Energy Resources Engineering, by courtesy and Senior Fellow of the Woods Institute for the Environment, by courtesy. He received a B.S. in Civil Engineering with distinction, an A.B. in Economics with distinction, and an M.S. in Environmental Engineering from Stanford University, in 1988. He received an M.S. in Atmospheric Sciences in 1991 and a PhD in Atmospheric Sciences in 1994 from UCLA. He has been on the faculty at Stanford since 1994. His work relates primarily to the development and application of numerical models to understand better the effects of air pollutants from energy systems and other sources on climate and air quality. He also supports work on the mapping and analysis of winds for wind energy. He has published two textbooks, "Fundamentals of Atmospheric Modeling" and "Atmospheric Pollution: History, Science, and Regulation," and over 75 peer-reviewed scientific journal articles. He received the 2005 American Meteorological Society Henry G. Houghton Award for "significant contributions to modeling aerosol chemistry and to understanding the role of soot and other carbon particles on climate." His recent paper, "Effects of ethanol versus gasoline on cancer and mortality in the United States" was the top-accessed article in the Journal Environmental Science and Technology April-September, 2007.

More Information
http://www.stanford.edu/group/efmh/jacobson/

Mark Z. Jacobson