Study Says Ethanol Pollution Could Rival Gas

A new study from Stanford University suggests that pollution from ethanol could be even worse than from traditional gasoline. Study author Mark Jacobson, of Stanford's department of civil and environmental engineering, explains.

Copyright © 2007 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

ALEX CHADWICK, host:

This is DAY TO DAY. I'm Alex Chadwick.

MADELEINE BRAND, host:

I'm Madeleine Brand.

Coming up, the worst school shooting before Virginia Tech has an anniversary this week. We speak with the principal of Columbine High School.

CHADWICK: First, with all the news about climate change, ethanol - that's fuel from corn - is supposed to be one answer. But now a study from Stanford University says ethanol pollution may be worse than gasoline. The problem is a byproduct of burned ethanol, a type of ozone.

Ozone is good when it's high up in the atmosphere, says the study's author Mark Jacobson, but it's very bad when it accumulates near the surface of the earth.

Prof. MARK JACOBSON (Author of Stanford University study on ethanol): It corrodes statues, it breaks down rubber. It also corrodes our lungs, causing respiratory illness and bronchitis and asthma. So there's - the bad ozone is what's being affected here by both gasoline and ethanol vehicles.

CHADWICK: So there would be more of this produced, you think, from using ethanol as a fuel?

Prof. JACOBSON: What we found was that in certain parts of the country, in fact most of the country - like in Los Angeles, in the northeastern U.S., in parts of the Midwest - you get increases in ozone due to converting to ethanol. If you weighed the changes in ozone by the population distribution of the U.S., you get a net increase in the death rate and hospitalization rate due to ethanol.

CHADWICK: So this surface ozone, I think you might call it, is this just simply a part of the process of producing ethanol, a natural byproduct, or is there some way you could filter this and get rid of it?

Prof. JACOBSON: Ozone that's formed is formed from the emissions of either ethanol vehicles or gasoline vehicles. And there - or have been technologies that have been introduced that have reduced the amount of ozone significantly. For example, the catalytic converter reduced the ozone. And there are other technologies that potentially could be used to reduce ozone further.

In fact, in this study we assumed there are going to be technological improvements. Just to put in perspective, gasoline vehicles in the United States kill about 10,000 people prematurely each year. Now, if we convert to ethanol, what I found was that this might increase slightly by about 200 deaths per year.

So it's not a large increase over gasoline. But the key is it's not an improvement over gasoline as has been suggested. The key is whether we can do a lot better than gasoline. And there are technologies out there that could eliminate all these deaths, particularly, battery electric vehicles where the electricity is provided by renewable energy such as wind and solar power. And also hydrogen fuel cell vehicles where the hydrogen is produced by wind and solar power and also hydroelectric geothermal power.

CHADWICK: I'm thinking beyond the scientific arguments to the political arguments. There is a huge, huge political base in this country in farming state for ethanol.

Prof. JACOBSON: On its own, if people want to use more ethanol that might be OK, but I would suggest not to use the argument that it benefits climate or it benefits air pollution. And particularly air pollution, because it simply does not benefit air pollution using ethanol.

And in terms of climate, the latest study shows - and that's out of U.C. Davis - that there's only a 2 percent difference in the net carbon emissions between ethanol and gasoline, which is virtually negligible - when the ethanol comes from corn.

CHADWICK: Mark Jacobson, when you publish this paper and you listen to the arguments and the predictions and the cost estimates and all that, why do you think we are where we are today where we seem to have arrived at ethanol as the answer?

Prof. JACOBSON: Well, the reason is is because there are a lot of people who have not been studying the subject for very long who are arguing in favor of ethanol and other types of solutions to climate change and also air pollution. And most of these people don't have a lot of background in this area and so aren't familiar with many of the issues.

Now, as somebody who's been working on this for many years looking at climate change and air pollution and energy issues, I can see that the solutions that have been proposed have many weaknesses to them. What I find is that a lot of this is driven by interest groups that - lobbyists in particular - and not driven by science.

So many times the scientists are not being listened to and instead it's the lobbyists who are being listened to, the venture capitalists in particular, but also lobbyists for particular industries.

CHADWICK: Mark Jacobson is an associate engineering at Stanford University. His article in the journal Environmental Science and Technology is out today. Professor Jacobson, thank you.

Prof. JACOBSON: Thank you very much.

(Soundbite of music)

CHADWICK: And NPR's DAY TO DAY continues.

Copyright © 2007 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.

Environmentalists Weigh In on Ethanol

Scott Olson/Getty Images
Scott Olson/Getty Images

During last month's State of the Union address, President Bush made it a federal goal to reduce the United States' gasoline usage by 20 percent during the next 10 years. It seems an environmentally friendly goal: Vehicle emissions are responsible for one-third of carbon emissions in the United States.

But some environmentalists are lukewarm about the replacement fuel Bush is backing: ethanol. They question the practicality and sustainability of the corn-based fuel.

Dan Becker, director of the Sierra Club's Global Warming and Energy Program, and Elizabeth Marshall, senior economist at the World Resources Institute, share their concerns:

Corn Vs. Cellulosic

Corn ethanol is presently the only commercially viable means of ethanol fuel production. It's made by distilling fermented simple sugars derived from corn. The problem is, it's still an environmentally taxing process.

"With ethanol, the devil is in the details," says Dan Becker. "There are ways of making it that are quite clean, but that's not the way we're doing it."

Becker backs cellulosic ethanol. If researchers can streamline what's still an experimental process, then ethanol could be made from a variety of plant materials.

The benefit of that, Elizabeth Marshall says, is that cellulosic ethanol production would allow farmers to grow crops that work in their area, rather than forcing corn on lands that are not well-suited to support it.

A Decrease in Greenhouse Gases?

Some environmentalists also question whether corn ethanol will ultimately help combat global warming. Dan Becker says it's necessary to take into account the energy expended to produce the fuel.

"The way we make ethanol now," Becker says, involves "seven passes over the field with a diesel tractor, heating the corn to convert it into ethanol, and transporting the fuel in diesel-guzzling trucks."

Marshall estimates that producing 15 billion gallons of corn ethanol – less than half of Bush's projected goal for 2017 – would increase greenhouse gas emissions from agricultural production by almost 8 percent.

Furthermore, Becker states, ethanol has a lower energy content than gasoline, so to meet the same energy demands, more gallons of ethanol would have to be produced.

A problem often cited with ethanol is that, when the production process is taken into account, it will ultimately release more greenhouse gas than gasoline. Becker says more recent studies show that's not the case. Overall, he says, corn ethanol isn't a loser but, "it's not a big winner, either. The best thing that we can say about ethanol is that it is not gasoline – and that is damning with faint praise."

The Environmental Footprint

Elizabeth Marshall worries that attempting to curb greenhouse gases with increased corn ethanol production will ultimately come at the cost of the country's water and soil.

"Soil erosion, nutrient runoff, and pulling new land into corn production are all concerns," she says.

To meet the increased demand for ethanol, many farmers want to bring into use lands that are currently protected. Marshall also predicts that higher corn prices will give farmers incentive to revert to environmentally unfriendly practices.

Farming's environmental footprint has always been a concern, says Marshall. "Increased demand for ethanol will only exacerbate existing problems."

FAQ: Why Ethanol Stations Are Hard to Find

Car tail pipe exhaust
Corbis

President Bush has seen into our energy future and named it ethanol. In his State of the Union speech last month, he called for alternative fuels to make up 20 percent of the U.S. fuel supply by 2017, and asked for $1.6 billion in a farm bill request to support alternative-fuel research. The fuel that currently shows the most potential is ethanol, which is mostly made from corn in the United States. Here, a look at what someday soon you may be asking for when you say at the pump, "Fill 'er up."

What's the benefit of ethanol over gasoline?

There's a lot of debate on this point. From all quarters of the United States, there's an increasing call to reduce dependence on fossil fuels. When burned, carbon-based fuels such as oil and coal release air pollutants, including the notorious greenhouse gases. Moreover, President Bush has made it a mandate to reduce America's reliance on foreign countries for its energy supply. One way to cut down on oil is to turn to alternative fuels, such as ethanol.

Can ethanol reduce greenhouse emissions?

A 2007 Congressional Research Service report says ethanol may slightly reduce greenhouse gases as an alternative to gasoline. But ethanol is a cleaner-burning fuel, but emissions released in the production of ethanol — manufacturing fertilizer for the corn and powering farm equipment and distilleries — have to be factored into the equation.

Can ethanol reduce dependence on foreign oil?

The CRS says ethanol does have that potential – by replacing gas in vehicles and in part because right now a lot of ethanol production is powered by natural gas or electricity from coal-fired power plants.

How much ethanol is currently being used?

Right now, about 5 billion gallons of ethanol was pumped into vehicles in 2006, a threefold increase since the turn of the century. But it's also a drop in the bucket compared with the amount of gasoline used — about 140 billion gallons in 2006. And only 1 percent of the ethanol used is the E85 blend — 85 percent ethanol, 15 percent gasoline. The other 99 percent contains only 10 percent ethanol, which offers significantly fewer environmental and energy benefits.

How many cars on the road can use ethanol?

The National Ethanol Vehicle Coalition estimates 6 million cars capable of running on E85 are on the road, compared with 230 million gasoline and diesel vehicles. But as of 2004, only 146,000 vehicles were actually using E85.

Why are so few cars using ethanol?

Not enough gas stations carry ethanol. Most stations that do are located in big corn-producing states, which cuts down on shipping costs. Out of the 556 stations nationwide that carry E85, only 118 are located along the East and West coasts. More stations are picking up ethanol, but shipping remains an issue. Ethanol can't be sent through gas pipelines; it has to be transported by truck, rail or barge.

So the benefits of ethanol aren't clear-cut yet. Why is there such a focus on it?

Environmentalists and Bush administration officials agree that corn-based ethanol is not the solution to our energy needs. For one, there isn't enough corn in the United States to make ethanol a significant replacement fuel. When Bush promotes ethanol, what he is banking on is the development of a still-experimental production process that would allow ethanol to be made from a variety of plants. Called "cellulosic ethanol," the process would cut down on the consumer cost of ethanol and use fewer carbon-based fuels to make it, thus reducing greenhouse-gas emissions even more. For instance, fields of prairie grass need much less help from fertilizers and farm equipment to grow.

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.

Support comes from: