December 16, 2014 | 1 Comment
University of Minnesota (UM) researchers found that vehicles using electricity from renewable energy could reduce the deaths due to air pollution by 70 percent. The study isn’t exactly simple. The findings come from a new life cycle analysis of conventional and alternative vehicles and their air pollution-related public health impacts.
From another view the study also shows that switching to vehicles powered by electricity made using natural gas also yields large health benefits.
The UM team did a new life cycle analysis of conventional and alternative vehicles and their air pollution-related public health impacts. The results have been published in the Proceedings of the National Academy of Sciences, without a paywall.
There are many renewable and natural gas points to celebrate. On the other side of the study are some disappointments.
Vehicles running on corn ethanol or vehicles powered by coal-based or “grid average” electricity are worse for health. The study alleges switching from gasoline to those fuels would increase the number of resulting deaths due to air pollution by 80 percent or more.
The team would have been less subject to incredulous criticism had they split out the source fuels for study. It very hard to imagine that there is a 150 percent difference from renewables to ethanol. Ethanol is after all a time tested renewable. Something isn’t ringing quite right here.
Chris Tessum, co-author on the study and a researcher in the Department of Civil, Environmental, and Geo-Engineering in the University of Minnesota’s College of Science and Engineering said, “These findings demonstrate the importance of clean electricity, such as from natural gas or renewables, in substantially reducing the negative health impacts of transportation.”
The University of Minnesota team estimated how concentrations of two important pollutants – particulate matter and ground-level ozone – change as a result of using various options for powering vehicles. Air pollution is the largest environmental health hazard in the U.S., in total killing more than 100,000 people per year. Air pollution increases rates of heart attack, stroke, and respiratory disease.
The team looked at liquid biofuels, diesel, compressed natural gas, and electricity from a range of conventional and renewable sources. Their analysis included not only the pollution from vehicles, but also emissions generated during production of the fuels or electricity that power them. With ethanol, for example, air pollution is released from tractors on farms, from soils after fertilizers are applied, and to supply the energy for fermenting and distilling corn into ethanol.
Of course the team didn’t note that those ethanol pollution factors would still be there if the corn, sugarcane or other crop was used in a different way. Its a sure thing that same thread of uses applies to the full range of energy sources in the study.
Bioproducts and Biosystems Engineering Assistant Professor Jason Hill, co-author of the study said, “Our work highlights the importance of looking at the full life cycle of energy production and use, not just at what comes out of tailpipes. We greatly underestimate transportation’s impacts on air quality if we ignore the upstream emissions from producing fuels or electricity.”
The UM researchers also point out that whereas recent studies on life cycle environmental impacts of transportation have focused mainly on greenhouse gas emissions, it is also important to consider air pollution and health. The study provides a unique look at where life cycle emissions occur, how they move in the environment, and where people breathe that pollution. Their results provide unprecedented detail on the air quality-related health impacts of transportation fuel production and use.
Civil, Environmental and Geo- Engineering Associate Professor Julian Marshall, co-author on this study said, “Air pollution has enormous health impacts, including increasing death rates across the U.S. This study provides valuable new information on how some transportation options would improve or worsen those health impacts.”
The UM professors have asked an important question, what energy sources for transportation offers the lowest pollution impact on people’s health. Its a question of more importance than the greenhouse gas thing. That’s about as far as the professors get before the bias shows up. Models, assumptions, simulations, and so forth might make for interesting reading and dramatic results and conclusions, but there is very little hard evidence in the less than 5 pages of reporting.
Moreover the study still rolls in the climate change aspect as a reason for the effort.
It looks like authors poured in a lot of effort on a worthy question and came away with a narrative that generally misses the point. An energy rich standard of living and life style does not come without costs. One is the damage done through air pollution. Other than clobbering corn ethanol and coal there isn’t much here. That seems to be the point.
Its fairly obvious that energy stores and sources that rely on processes without chemical combustion are going to be advantageous. Its also plain that combustion isn’t particularly efficient as there is always heat to be used or lost.
Its a great question to be raised, but the route to useful information in planning a better more energy rich and healthier future has simply been missed.