Honeybees construct perfectly hexagonal combs and surmount architectural challenges by altering their building behavior.
Image credit: Michael L. Smith.
Edited by Douglas J. Arent, National Renewable Energy Laboratory, Golden, CO, and accepted by the Editorial Board November 8, 2014 (received for review April 15, 2014)
Significance
Our assessment of the life cycle air quality impacts on human health of 10 alternatives to conventional gasoline vehicles finds that electric vehicles (EVs) powered by electricity from natural gas or wind, water, or solar power are best for improving air quality, whereas vehicles powered by corn ethanol and EVs powered by coal are the worst. This work advances the current debate over the environmental impacts of conventional versus alternative transportation options by combining detailed spatially and temporally explicit emissions inventories with state-of-the-science air quality impact analysis using advanced chemical transport modeling. Our results reinforce previous findings that air quality-related health damages from transportation are generally comparable to or larger than climate change-related damages.
Abstract
Commonly considered strategies for reducing the environmental impact of light-duty transportation include using alternative fuels and improving vehicle fuel economy. We evaluate the air quality-related human health impacts of 10 such options, including the use of liquid biofuels, diesel, and compressed natural gas (CNG) in internal combustion engines; the use of electricity from a range of conventional and renewable sources to power electric vehicles (EVs); and the use of hybrid EV technology. Our approach combines spatially, temporally, and chemically detailed life cycle emission inventories; comprehensive, fine-scale state-of-the-science chemical transport modeling; and exposure, concentration–response, and economic health impact modeling for ozone (O3) and fine particulate matter (PM2.5). We find that powering vehicles with corn ethanol or with coal-based or “grid average” electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by low-emitting electricity from natural gas, wind, water, or solar power reduce environmental health impacts by 50% or more. Consideration of potential climate change impacts alongside the human health outcomes described here further reinforces the environmental preferability of EVs powered by low-emitting electricity relative to gasoline vehicles.
Footnotes
- ↵1To whom correspondence may be addressed. Email: hill0408{at}umn.edu or julian{at}umn.edu.
Author contributions: C.W.T., J.D.H., and J.D.M. designed research; C.W.T. performed research; C.W.T., J.D.H., and J.D.M. analyzed data; and C.W.T., J.D.H., and J.D.M. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission. D.J.A. is a guest editor invited by the Editorial Board.
Data deposition: The data reported in this paper has been deposited in the Data Repository for University of Minnesota (DRUM), dx.doi.org/10.13020/D6159V.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1406853111/-/DCSupplemental.
Freely available online through the PNAS open access option.
Air quality impacts from light-duty transportation
Article Classifications
- Physical Sciences
- Environmental Sciences
- Social Sciences
- Sustainability Science
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