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Stanford Study on Ethanol Emissions Generates Counter Arguments and Rebuttal
26 April 2007
Last week’s publication of an article in Environmental Science & Technology (ES&T) by Stanford University professor Mark Jacobson, in which he projects that fleet-wide use of E85 in the United States could increase the number of respiratory-related deaths and hospitalizations (earlier post), has stimulated counter arguments from several groups, including various state American Lung Association organizations, the Natural Resources Defense Council (NRDC) and the American Coalition for Ethanol.
In his paper, Jacobson concluded in the abstract that “Due to its ozone effects, future E85 may be a greater overall public health risk than gasoline. However, because of the uncertainty in future emission regulations, it can be concluded with confidence only that E85 is unlikely to improve air quality over future gasoline vehicles. Unburned ethanol emissions from E85 may result in a global-scale source of acetaldehyde larger than that of direct emissions.”
In remarks outside the paper, Jacobson was somewhat more aggressive in characterizing the results of the study.
Today, there is a lot of investment in ethanol, but we found that using E85 will cause at least as much health damage as gasoline, which already causes about 10,000 U.S. premature deaths annually from ozone and particulate matter. The question is, if we’re not getting any health benefits, then why continue to promote ethanol and other biofuels?
There are alternatives, such as battery-electric, plug-in-hybrid and hydrogen-fuel cell vehicles, whose energy can be derived from wind or solar power. These vehicles produce virtually no toxic emissions or greenhouse gases and cause very little disruption to the land—unlike ethanol made from corn or switchgrass, which will require millions of acres of farmland to mass-produce. It would seem prudent, therefore, to address climate, health and energy with technologies that have known benefits.
The American Lung Association of the Upper Midwest—a strong supporter of the use of E85—countered first by focusing on the assumption in the study that all vehicles will be operating on E85 in 2020.
E85 was never intended as a complete gasoline replacement, and will only be capable of achieving a portion of the total US fuel demand. Additionally, the areas of the county where this study demonstrates E85 to have the most harmful effects are where E85 is not currently manufactured or sold, making them the least likely areas of concern.
Additionally, the ALA noted that while ethanol-based fuels may increase the emissions of aldehydes, it reduces two air pollutants linked to cancer, benzene and butadiene. (Both those results of the use of ethanol fuels are reported in the Jacobson paper.)
Finally, the American Lung Association noted that Jacobson had not addressed the reduction in carbon dioxide emissions associated with the use of E85.
The NRDC identified what it characterized as a number of flaws with the paper, and recommended two steps to clarify the results of the paper, and take action if warranted:
First, that a team of leading vehicle emission experts review the existing data on emissions from E85. Based on this review, if the panel believes the emission scenarios in Dr. Jacobson’s study are incorrect and/or additional sensitivity runs are necessary, air pollution regulators should re-run the air pollution model to develop a broader scientific consensus of the impacts on air quality.
Second, based on the results from the above work, NRDC urged the CARB, US EPA, automakers and the ethanol industry to commit to additional testing of E85 vehicles if warranted. If such testing results indicate a need, we call upon CARB and US EPA to immediately set tighter emission standards on E85 vehicles to protect public health.
NRDC made a number of pointed comments on the contents of the paper, including:
The study finding conflicts with findings by US EPA, US DOE and NREL that found that E85 can reduce emissions of smog-forming chemicals.
The study’s assumption that E85 emissions are substantially different than those of gasoline is incorrect.
The study’s findings are primarily driven by assumed decrease in NOx.
The study ignores the potential global warming pollution reductions from E85 and the smog impact of rising temperatures caused by global warming.
In conclusion, the NRDC said,
The author’s comments surrounding the release of his study overstate what the study actually shows. An accurate summary would be that this study shows that use of high blend ethanol is unlikely to significantly improve air quality compared to use of gasoline.
—NRDC
In response to all of the above plus other comments in the press and from other organizations, Jacobson published a detailed rebuttal of the various charges on his web site at Stanford (with the promise of additional rebuttal to come, as of 26 April).
As to the general charge of a misleading study due to the assumption of 100% penetration of E85, Jacobson noted:
The study makes no exaggerations as it does not claim that E85 will or is likely to make a 100% penetration. The purpose of looking at 100% penetration was to determine an upper limit of the effects from which the effects of any smaller addition of geographically-dispersed vehicles can be examined. Once the 100% effects are known, the effects of incrementally-adding a few geographically-dispersed vehicles can be estimated. It is the direction of the effects, not the magnitude, that is important in this case.
Nor was he swayed by the argument about greenhouse gases, characterizing the potential reduction, based on recent life cycle analyses, as too low. Concerning the NRDC paper, Jacobson noted:
In this document, NRDC has suppressed information contrary to its argument, misstated assumptions and conclusions in the paper, and failed to comment on the real issue, the comparative disadvantages of both ethanol and gasoline compared with other existing and emerging technologies that nearly eliminate air pollution, climate relevant gases, and use much less land area than corn or prairie grass for ethanol.
Resources:
“Effects of Ethanol (E85) Versus Gasoline Vehicles on Cancer and Mortality in the United States”; Mark Z. Jacobson, Environ. Sci. Technol., ASAP Article 10.1021/es062085v S0013-936X(06)02085-2
NRDC Statement on New Study of Ethanol (E85) Impact on Air Quality
Responses to Comments by the Ethanol Coalition, Roland Huang (NRDC), Gary Whitten (Consultant), and an unauthored NRDC document (Mark Jacobson)
April 26, 2007 in Emissions, Ethanol | Permalink | Comments (45) | TrackBack (0)
Comments
Posted by: ben | April 27, 2007 at 03:50 PM
Why can't we use solid biofuels to produce electricity to power EVs? If we take this path, we can generate electricity and stuff the carbon from the combustion of the biofuels underground (carbon capture and storage / or soil sequestration). That way, we have a 'carbon-negative' energy system that takes more CO2 out of the atmosphere and takes us back to a pre-industrial age, while still powering our societies. This can't be done by wind or solar, can it?
Posted by: Gio | April 27, 2007 at 07:31 PM
If you read the Standford study the results on Table 1 show clearly that nearly all 30 measured pollutants are reduced by an average of 75-80% compared to gasoline. For the time that ethanol will be used to transition to BEVs, the "health risk" is acceptable.
Again, spinning for controversy is an exercise in exercises. Busywork of dubious value.
And if people walked more then the donkeys would inherit the earth.
Posted by: gr | April 27, 2007 at 11:02 PM
Gio,
Its a good idea, but not as compelling as others. Biomass is a great source of carbon, which electricity and hydrogen can't replace (unless someone revives the art of alchemy). Biomass could be used to make things like plastics (fermentation pathways, polylactones) composites and asphalt (gasifiction, prolysis) which if not burnt act as carbon sinks, so not only are you carbon negative but you also make a profitable product. Trying to store CO2 is a questionable and energy intensive task, trying to store asphalt isn’t.
Posted by: ben | April 28, 2007 at 05:38 AM
I think the problem is people have to stop giving the middle east so much of our money, and that is the number 1 concern ....they want us all dead, what ever we do is better than buying there oil..
Posted by: Perry | April 28, 2007 at 05:42 AM
This is kind of where CO2 and fossil fuels overlap. If the world gets serious about CO2, then they get serious about fossil fuels. We get several benefits with one change. We can save finite fossil fuels for later use, clean up the air, reduce foreign imports and reduce CO2 emissions. If people like former CIA chief Woolsey are correct, we can stabilize the world situation as well. There would be fewer conflicts over scare resources that will bring huge amounts of hard cash. I would like to see a day when there is still oil in the ground, but there is not such a demand for it to keep our economies running.
Posted by: SJC | April 28, 2007 at 07:25 AM
No matter what the best deal looks like, the economical factor is the main factor. It wont change anything if a sciencetist or two give a warning about the end of the world.
The end of oil age will not because of people's concern of environment, nor because of oil rigs drying up. Just like the end of stone age not because we are running out of stones.
---
Some buddy above mentioned about the vast idle spaces in city mainly in rooftops, car parks, its everywhere. If we are to make those place productive, it would do the world and yourself a big flavour. Not just putting solar panels on rooftops, but simply install dipping system and farm some tomatoes on an apartment rooftop would helps preserving a few more trees being chopped. Not to mentioned the panels/plants absorb heat from sun and reduce AC cost a bit - it would be better then switching off the lights of the whole city for an hour.
Why would people keep dipping into biofuel? Especially ethanol, lower mileage, less power, more cost, and lots of farmers got occupied behind the scene. At least not with the fuel guzzler roaming the street. A Hummer with E85 simply spells the word destruction.
Posted by: rexis | April 28, 2007 at 08:37 PM
One probably doesn't need be a scientist to realize that the next half decade will see "steps" taken to getting to more efficient PV's, etc. Once our US government can see the effectiveness to subsidizing our personnal choices for home PV deployment (not troop deployment), our society will have a chance at not becomming a "third world" community. We're fast losing our real estate, businesses, car industry, etc.
We're not competitive in any of our industries. Our country MUST start to save the national money now sent over to the OPEC countries for oil. We shouldn't be driving HUMMERS, we shouldn't be questioning the oil shortage, we shouldn't be putting off installation of PV on everything around. It's just an inevitability that a passive producer of electricity will predominate.
So you can see, one need not be a scientist to realize this, or speak with eloquence and scientific jargon. :)
Posted by: FBerry | April 29, 2007 at 05:36 AM
Bear with me on this thought......
What if the government decided to pay for 100% of any BiPV system; one that could actually do the job for any given home with an excess of power generation? Let's say that a system should produce 10% excess by design.
Start in sunny states to hasten the money recovery; pay attention Arnold (and start slowly by trial communities.)
What if the government in doing so, would legally and ethically collect electrical revenues so generated by the excess power from these systems. This money would be used to replace ageing equipment over the decades and further develope next Gen. PV technology, as well as subsidizing our ageing power grid. It wouldn't be used for war reparations, or any other bull $%$$.
Making money passively is not something that the government is doing other than taxing the %#$$%^* out of us.
Posted by: FBerry | April 29, 2007 at 05:56 AM
I see no reason why the government can not compete with the private sector and make a profit. I know this is a radical idea, but why not? As far as renewable energy goes, the figure I have heard is 20%. Beyond providing 20% of the grid power with renewable sources, the now and then nature of wind and sun can make the grid unstable. This may not be entirely true, but everything has limits.
Posted by: SJC | April 29, 2007 at 09:16 AM
Ben,
In response to your response to Gio. You're right about biomass as a means of potential carbon sequestration as charcoal, but it could also be a plentiful source of electricity. See http://www.theoildrum.com/story/2006/11/27/0432/3533 for a well thought out proposition, by the blogger Engineer-Poet, for using biomass to generate primarily electricity and making ethanol from the emissions from the electricity generation. Direct Carbon Fuel Cells are a promising means of converting great sources of carbon like biomass into electricity.
Posted by: basline | April 30, 2007 at 01:30 PM
Basline,
I kind of disagree, it would be best to use biomass as a carbon source. If you can make both electricity and optimize carbon recovery then that fine by me. But gasification and pyrolysis processes can loss a significant amount of carbon as CO2, fermentation processes have better carbon efficiencies at making specific products from specific biomass sources (which is both their weakness and there advantage). It might be best to run fermentation on biomass and then run gasification or pyrolysis on the left over unfermentable biomass.
Posted by: ben | May 01, 2007 at 05:49 PM
Perry,
You make your own bed...
Posted by: skropp | May 02, 2007 at 01:51 AM
Perry,
You make your own bed...
Posted by: skropp | May 02, 2007 at 01:51 AM
""The meek shall inherit the earth"
Since the time that was written (2000 years ago?),
the exact opposite has been true.
The crusades.
colonialism.
slavery.
resource extraction from poor countries to rich countries.
Why do think that pattern will change?"
Because the exploitation is unsustainable, and little changes like colony collapse disorder(honey bee)and low birth rates will leave the indigenous people in LDCs and the Amish (the meek) as the only ones with the skills to feed themselves.
Posted by: John Schreiber | May 05, 2007 at 06:47 AM
Amazing thread...what about BIOBUTANOL?
Isn't Dupont working with some startups on organisms to make cellulosic biobutanol? It has many advantages over ethanol. What's the pollution story there?
Posted by: C Harget | May 10, 2007 at 12:33 PM
Is it true that Stanford received a $50 Million dollar Gift or grant from Exxon!!
Posted by: Croft | June 20, 2007 at 09:41 AM
how is e85 a bad and good thing?
Posted by: | October 31, 2007 at 06:11 AM
check this out-
www.teslamotors.com
and it only costs 100k cuz its a supercar.
its possible, just needs to be reduced in terms of power/speed.
Posted by: brian | March 20, 2008 at 02:59 PM
From studying the emissions data of ethanol I'd have to say that deriving a cleaner burning fossil fuel is still our best option until our electrical alternatives are more cost effective and less costly in buy into. There are additives that can be used to reduce the harmful emissions of the current generation of internal combustion engines. I know as a stop gap measure to mitigate the level of pollutants this might be more feasible, cost wise, to the very day consumer given the current economic situation.
Going green shouldn't increase the risk to our health, the environment or our overall quality of life. I think that the impacts of ethanol usage out-weigh it's supposed benefits greatly.
http://topfuel.wordpress.com/
www.topfuel-performance.net
Posted by: inthebarrel | May 20, 2008 at 09:40 AM
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The meek will inherit the earth... when the technological singularity comes and everyone but the Amish, fundamentalist, etc are assimilated by our new cybernetic overlords!
I can see the day coming when Amish will be riding their horse powered buggies around with signs on the back that say “Biofuel powered since 4000BC” just to spite us.
Stan Peterson, first of all biofuels don’t “produce” CO2 likes oil,coal,NG do. All the CO2 given off by biofuels is reabsorbed when plants are grown to make more biofuels, hence carbon net neutral, in fact recent studies show some biofuels could be net negative with a constant input of carbon back into the soil! But you probably don’t care.