Ethanol and the Environment

As I continue to work on an Ethanol FAQ, I again wanted to solicit feedback from readers on the following question:

What about the environmental benefits of using ethanol as fuel?

The feedback I received on the previous posting on ethanol use and foreign oil displacement was very valuable in helping me to identify poorly communicated points, and make some key edits. I am hoping for the same kind of feedback on the present offering. I would also ask readers to take a look at the questions I have tackled in the FAQ, and let me know if there are glaring omissions, errors, typos, or items requiring additional clarification. I will continue to post some portions of the FAQ here for feedback, with the intent of posting a finished product within a month or so. And although it seems like all I have been posting on lately is ethanol, I don't expect that trend to continue following completion of the FAQ.

There are environmental benefits, as well as negative environmental consequences from using ethanol as fuel. If the ethanol is produced from industrial corn farms, more negative environmental consequences can be added.

Because of ethanol's marginal energy balance, there is a marginal reduction in greenhouse gas emissions per distance driven. Researchers have also found that ethanol produces less carbon monoxide when it is burned in an internal combustion engine.

On the other hand, ethanol raises the vapor pressure when blended with gasoline, which causes an increase in smog. In an August 1, 2007 article in the Houston Chronicle (now archived, but available at the following link):

Five questions with Cal Hodge

Q: We're already using more ethanol in our fuel now, because of the outcry over the fuel component methyl tertiary butyl ether or MTBE and its propensity to foul groundwater. You had warned that replacing MTBE with ethanol could hamper efforts in cities like Houston to improve air quality because of these problems with volatile organic compounds and nitrogen oxides. So has that actually happened?

A: Yes, it has happened. Los Angeles is the cleanest example. They began switching from MTBE to ethanol in 2001. But when they made their major switch in 2003, there was a significant decrease in air quality. They basically stopped making progress toward attainment on EPA's ozone standards when they switched to ethanol. When using MTBE, with the cars getting cleaner each year, coupled with a very clean fuel, Los Angeles was on a straight-line path toward attaining EPA's air standards by about 2002 or 2003. Now that they have switched to ethanol, the trend line indicates nonattainment for many years to come.

A 2007 research paper by Stanford University professor Mark Jacobson echoes that claim:

Effects of Ethanol (E85) Versus Gasoline Vehicles on Cancer and Mortality in the United States

In this paper, Professor Jacobson studied the potential impact to air quality as more E85 vehicles hit the roads, and he concluded:

"In sum, due to its similar cancer risk but enhanced ozone health risk in the base emission case, a future fleet of E85 may cause a greater health risk than gasoline. However, because of the uncertainty in future emission regulations, E85 can only be concluded with confidence to cause at least as much damage as future gasoline vehicles.

Because both gasoline and E85 emission controls are likely to improve, it is unclear whether one could provide significantly more emission reduction than the other. In the case of E85, unburned ethanol emissions may provide a regional and global source of acetaldehyde larger than that of direct emissions."

In addition to the mixed environmental impact of directly burning ethanol as fuel, industrial corn farming has significant negative environmental impacts. From a 2006 paper that evaluated ethanol and biodiesel:

Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels

Both corn and soybean production have negative environmental impacts through movement of agrichemicals, especially nitrogen (N), phosphorus (P), and pesticides from farms to other habitats and aquifers. Agricultural N and P are transported by leaching and surface flow to surface, ground, and coastal waters causing eutrophication, loss of biodiversity, and elevated nitrate and nitrite in drinking-water wells. Pesticides can move by similar processes.

The markedly greater releases of N, P, and pesticides from corn, per unit of energy gain, have substantial environmental consequences, including being a major source of the N inputs leading to the ‘‘dead zone’’ in the Gulf of Mexico and to nitrate, nitrite, and pesticide residues in well water. Moreover, pesticides used in corn production tend to be more environmentally harmful and persistent than those used to grow soybeans.

Two additional factors not discussed in the article are 1). Industrial corn farming depletes the topsoil, putting future generations at risk:

Peak Soil: Why cellulosic ethanol, biofuels are unsustainable and a threat to America

Row crops such as corn and soy cause 50 times more soil erosion than sod crops [e.g., hay] or more, because the soil between the rows can wash or blow away. If corn is planted with last year's corn stalks left on the ground (no-till), erosion is less of a problem, but only about 20% of corn is grown no-till. Soy is usually grown no-till, but insignificant residues to harvest for fuel.

2). Corn farming and subsequent conversion to ethanol consume enormous amounts of fresh water:

Experts Differ About Ethanol-Water Usage

In this article, David Pimentel is the pessimistic expert who claims that when you add in the water required to grow the corn, it takes 1,700 gallons of water per gallon of ethanol produced. The "optimist" in the article, Derrel Martin, an irrigation and water resources engineer, said:

Martin said the question of whether increased corn production and the irrigation it requires will overburden the state's water supply is an important one that does not yet have a clear answer.

Additional research has been reported by two Colorado researchers:

Biofuels: The Water Problem

In late June, two Colorado scientists, Jan F. Kreider, an engineering professor at the University of Colorado, and Peter S. Curtiss, a Boulder-based engineering consultant, presented their peer-reviewed report, “Comprehensive Evaluation of Impacts from Potential, Future Automotive Fuel Replacements” at a conference sponsored by the American Society of Mechanical Engineers. The two found that producing one gallon of corn ethanol requires the consumption of 170 gallons of water. That figure includes the amount needed for all irrigation and distillation. For comparison, the two scientists estimated that each gallon of gasoline requires just 5 gallons of water. If Kreider and Curtiss are right, the 5 billion gallons of corn ethanol produced in America in 2006 required more water than production of the 140 billion gallons of gasoline the U.S. consumed that year.

Ethanol proponents have largely downplayed the negative environmental impacts of increased ethanol production, while emphasizing the positive impacts. But by ignoring the negatives, all of us, and future generations, are being put at risk.

Personal Note

Some of you may have noticed that I haven't been contributing much lately, nor posting with much frequency on my blog. I explained the reasons for this in a recent blog posting, but I just want to reiterate the point here. In an effort to more efficiently allocate my time, I am limiting my writing efforts. It had gotten to the point that I was literally working 45 hours a week at my regular job, 45 hours a week on my blog, and my family was wondering why I wasn't doing more things with them.

I had considered the idea of just stopping cold turkey, but I believe the issues that we discuss and debate are of paramount importance. But, so are the other things in my life. So, I have come to a compromise solution. In order to eliminate the things that consume most of my time, I have essentially stopped participating in the comments sections (here and on my blog), I have taken my e-mail address offline, and I am limiting myself to writing in the early morning when I usually have some time before the family wakes up. What I have told them is that I intend to keep writing, albeit greatly scaled back. They are very supportive of what I am trying to accomplish (in fact, my 13-year old daughter told me yesterday that she wants to learn to be more environmentally responsible). My intent is for my writing to be transparent to my family and my employer. If I can't manage that, I will have to quit altogether. But I will manage it.

if you are so inclined...our authors thank you for your support.


I want to thank you for all the time and effort you have expended in getting to the truth about peak oil and the ethanol hoax in particular. Your fair-minded efforts have made a real difference in the energy policy in the U.S., if nothing else I believe you've slowed down the implementation to where wiser heads will stop the ethanol insanity hopefully before there is so much investment that its unstoppable.

I just like to ecco Bob's reply , thx RR.

The real core understanding of bio-fuels and EROEI - is IMO the most important as to how policies are(will be) formed today .... for the future...

Are biofuel/EROEI as complex as the global-warming issue (?)
- personally I dont think so.


Robert – It is a tall order to analyze all sorts of implications regarding circumstantial issues on bio-fuels.
I’m not saying it’s not important, but I feel focusing the VERY fundamental core issue should be priority no.ONE.

The fundamental issue is EROEI, and preliminary claims for bio EROEIs – ranges between, NEGATIVE (e.g. forget it) and 8:1 sugarcane/ethanol’s from Brazil (keep going)…. but mostly I have been reading cites of 1,3 :1, and hold this for true (for a second)

Then, a mental and philosophical challenge follows – Just for a second try to envision planet Earth without fossil fuels – whatsoever …..

Would the Industrial Revolution have taken place – on such a skinny energy diet? Remember the 100:1 EROEI for oil, initially...way back in 1859.

Because, actually the BIO-HYPES of today are coming main stream to replace the very origins of the Industrial Revolution, namely coal, oil and gas…!

The easy way of scrutinizing ALL kinds of renewable energy producing fuels and equipments are :::

MAKE their products made by their own produced power – THEN we will see what they are …..
and the EROEI will be so easy to spot, because those going out of business do not deliver ON THE REASON FOR THEIR BUSINESS …

as I see it!

The historic debates on whether and by how much the energy gain of ethanol was positive have been a red herring. Irrespective of that bottom line, the other limiting inputs to corn ethanol make it far inferior to gasoline. Even if cellulosic ethanol lives up to its claims of higher energy return (which I find doubtful because the initial ethanol solution is less concentrated than with starch ethanol) it will still have the scalability problems of other limiting inputs.

But it is natural to want to find a 'replacement' for something, in fact we are conditioned to do so. In the end, changing our way of life and moving away from the internal combustion engine will serve us much better than scaling up land, material, soil and water inputs to create an inferior fuel. But it will take time for this message to sink in, because its a very difficult one (at first) to accept.

I'm mostly concerned about water. David Pimentel told me the Kreider study seriously understates the amount of water needed for corn ethanol, which is presumably a boundary issue which Im trying to suss out.

About 10.2 kg of corn is required to produce 1 gallon of ethanol. The average water requirement per kilogram of biomass is 1,000 liters. In Pimentels latest water paper they report that 650 liters of water are required to produce 1 kg of corn. This means 6630 liters of water for just the corn in 1 gallon of ethanol - or about 1754 gallons of water. And still a little more water is required in the fermentation and processing operation.

Water, like oil, is seemingly cheap, unless one lives in Western US. As nasty as oil and gas production are, they at least limit their environmental impacts to small land areas relative to biofuel production.

Systems analysis at the highest levels of government needs to address the linkages between water and energy. Fully 50% of our nations water use goes to the energy sector already. If we scale non oil and gas energy sources - what will this mean for water? In the end I think most of us would rather drink than drive...

Logically, it seems silly to try and shove the sun through a corn cob to get energy.

If we use solar power directly, we would get durable energy at an affordable price. If all the highways in the US had 20 feet of solar collectors over them, we would harvest 27 Quads (10 watts/square foot); an amount equal to the energy currently consumed by transportation.

Using JPods instead of cars, replace moving a ton to move a person and strive to move only the person, we can cut the energy budget to 6.8 Quads (5 for oil, .8 for JPods).

The solar collection creates a surplus of power of about 6.2 Quads. The collection is 1.4 million miles of JPods rail with solar collectors 8 foot wide.

There is a synergy between the distributed nature of the transportation grid and the distributed energy from sunshine.

Thomas Edison, 1910:
"Sunshine is spread out thin and so is electricity. Perhaps they are the same, Sunshine is a form of energy, and the winds and the tides are manifestations of energy.”

“Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property.

“There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces. Electricity ought to be as cheap as oxygen...."

Historical Curiosity: I wonder what our world would look like today if Edison had teamed up with Eistein based on Einstein's 1905 proof of Quantum Mechanics based on the PhotoElectric Effect. Sunshine and electricity might cost nearly the same.

It also seems likely that burning food in cars that are less than 1% efficient is environmentally as unwise as burning oil. In normal commuter travel, cars have a Parasitic Energy Consumption (ratio of moving mass to mass of cargo and passengers) of about 300.

There is no energy crisis. Government planning and monopoly of transportation and energy has brought us to where we are. If we wish to have a different future than Peak Oil and Global Warming we need de-monopolize energy and transportation as we de-monopolized communications in 1984.

Germany broke the government monopoly of energy with the policy where anyone can be a power company, sell surplus electricity to the grid at 20% over cost to buy. The result is an explosion of innovation and 100,000 new jobs in the solar industry.

To create environmentally sound transportation and energy, we need an environment that allows creativity.
It costs less to move less

By your argument an electric bike would be even better than a JPod, since it uses even less energy to move even less mass.

I love electric bikes, but I can't see American auto traffic switching from cars to bikes without going through a scooter phase first. It would be too dangerous to mix bikes with 70mph SUVs.

Your point that photovoltaics waste less energy is correct, if we forget the energy it takes to manufature and maintain photovoltaics:

There will be a lot of niche solutions. Electric bikes are a great solution for many uses.

Carrying luggage, elderly, children, families, cargo and other transport needs may not be ideal of bikes. The primary niche for JPods is highly repetitive travel less than 30 miles.

I do not know how everything will turn out but do believe the sooner we implement a diverse set of options the more durable our economy will become.
It costs less to move less

A step up from an electric bike would be to get a GEM glorified electric golf cart. Seats four, some cargo, range of 40 miles. When I commute to work, I don't take the family or cargo. Recharge the battery from solar panels if you want.

I would like to see a 48 VDC electrified line that any and all light electric vehicles can tap into. They can bill you for what you use. If I got a bike and you got an electric locomotive, we can both tap the same power rail but your bill will be bigger than mine.


I haven`t escaped from reality. I have a daypass.

I think there will be a great niche for golf carts also. We plan that personal JPods can drop onto a golf cart frame for last mile solutions.

A key issue for the golf cart market will be safety on high ways with mixed vehicle traffic. Morgantown PRT has logged 110 million injury free passenger miles.

The ability of JPods to travel in a different plain than current traffic has speed, safety and capacity benefits. Automated travel provides mobility regardless of age or ability.

I second your motion for a dedicated right of way for light electric vehicles.


I haven`t escaped from reality. I have a daypass.

I am also eager to see more development for just plain bikes, as well, or electrics that attach/detach easily. I'd like to see commuter trains built with 'Biker Cars' (and Biker Bars?), so we can have 'intermodal commuting' .. your legs do the first-mile and the last-mile, easy!

re: The Scotsman article..
This was in Drumbeat a few weeks ago. I'm afraid it hasn't improved much with age.

Here is my first of a handful of comments below that unfortunate article;

"..."according to a study by scientists"

"The research was carried out by a team in Greece.."

Who is this reporter? Daniel Parker needs to connect this claim to a trackable group or institution for this article to have any meaning. This is as fresh as the Foreward in Michael Crichton's 'State of Fear', which claims that, tho' fiction, the work represents the findings of 'real scientists at real universities'. Oh my!

According the the US's NREL, or National Renewable Energy Labs, a solar electric installation will recover its embodied energy, including the aluminium and other 'balance of system' (BOS) components in 2 to 5 years, depending on which technology is used plus other particulars. Anything that requires a fuel input to operate is, by definition never able to recover all it's energy inputs, since they are continually being added on top, while pollution is spilling out the backside.

They don't mention the advantages that we can get from rooftop solar to gird against the increasing likelihood of grid failures (I'm assuming for UK, the US is certainly lagging), whether caused by intense weather conditions or underinvestment in maintenance, probably both. Distributed generation, with both Solar and Wind will help to level the loading on the wires so that overcapacity disruptions (meltdowns) can be lessened, and remote areas can continue self-generating when key links have gone down.

Here are two links with some checkable findings..

Best Hopes for responsible reporting!
Bob Fiske

-- should be noted from the NREL study that the best of these panels can recover their embodied energy in about one Year, when you're not counting the BOS components.

Bob Fiske,

You're right that the Scotsman article is weak. Your first link is broken, too.

Your second link asserts that PV panels pay back their energy investment in a few years, but doesn't explain how. I'm meant to assume that this is usable energy captured from a day of average length. I'm going to need a little more information before I can decide anything. A Googling I go.


Here's Wiki's statement. The NREL link was clipped, but I can't find it there right now..

Under the EROEI section
" Crystalline silicon PV systems presently have energy pay-back times of 1.5-2 years for South-European locations and 2.7-3.5 years for Middle-European locations. For silicon technology clear prospects for a reduction of energy input exist, and an energy pay-back of 1 year may be possible within a few years. Thin film technologies now have energy pay-back times in the range of 1-1.5 years (S.Europe).[42] With lifetimes of such systems of at least 30 years, the EROEI is in the range of 10 to 30. "

" Logically, it seems silly to try and shove the sun through a corn cob to get energy. "

I LOVE this sound bite! Photo Sharing and Video Hosting at Photobucket

" Logically, it seems silly to try and shove the sun through a corn cob to get energy. "
Gene said,
I LOVE this sound bite!
It's good alright, and combined with the Edison quote referring to solar/wind,
“Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property."

These two quotes just about says it all, don't they? :-)



I broadly agree with your analysis. When one considers the resource inputs, especially water, corn-based ethanol does seem like an environmental war crime.

But I wonder why you don't take it to the next level. Why don't we ban high fructose corn syrup? Given that this foolish corn-based ethanol quest is recent and may well be short lived, the syrup seems like a greater offender.

It seems the the best solution here would be better pricing of water resources. If your figures are correct, which I assume they are, I would assume that subsidized water supply to corn farmers is as much the problem as anything else.

The problem is that it is very difficult to separate uses of corn. In an ideal world, maybe water used for nutricious foods (corn, flour, etc) would have a low tax. Corn dogs and popcorn a bit higher, corn syrup and ethanol the highest. Removing subsidies for ethanol is obviously the right first step, but if the goal is to better use our natural resources, there are other culprits.

Anyone who rants about how destructive our vehicle based lifestyle is, but eats more than a few ounces of beef per day, or drinks soda, would appear a tad hypocritical.

Anyone on this list who hasn't should read Omnivore’s Dilemma. Polan barely talks about ethanol but spends several chapters on corn and how absurd our big agribusiness system is. Adding fuel to the mix only makes it a little more absurd because very little of the cultivated acreage of the U.S. is devoted to directly feeding people, much less to fueling vehicles. The majority of corn goes into cow-feed and soda pop, neither of which is smart or necessary. Seems to me that long before we have to choose between growing food or fuel, we will have to choose between fuel and Pepsi, call it the “New Pepsi Challenge” if you like. Already, due to “peak soil” we are in reality faced with a choice between soda and food, and healthful food and marbled beef. The fuel or food dichotomy, at least in North America, is a red herring.

Hi Jack,

I really like your points here. I wonder if there is any way (time?) to do some analysis and quantify...I suppose it might not be too difficult, if one were to look at money flows of the corn syrup industry, and then look at percent water use of total ag use this represents. (Still would be some work, though.)

Also, do you have any idea about numbers - annual production numbers: HF corn syrup v. ethanol?

re: "subsidized water supply to corn farmers" and "...corn syrup and ethanol the highest..."

The thing is, it seems like one could make the exact same argument for, say, packaging of all kinds. In this case, it would be oil and/or wood products (?), as opposed to water. They use more resources - (?)- than say, bulk grains from bins at the co-op, - though, too, might be a wash, if people use plastic bags to weigh out unpackaged items.

Addressing this in a positive complicated. If you don't tax the corn farmer, but you then tax the "value-added" food products corp. - what's to say? People might end up still going for fast food.

Still, it's a good idea.

re: "there are other culprits."

So, what do you think? A plastic bottle tax? Ban? Ration fast food?

Edit: The graph w. "Dry weight, pounds per capita per year" is interesting.

It looks like the Avg. American consumes right around his/her weight in sweeteners each year. (?)

Also, do you have any idea about numbers - annual production numbers: HF corn syrup v. ethanol?

I don't have figures, but will try to look them up and make a rough approximation. The problem may be getting all the conversion figures (corn the corn syrup versus corn to ethanol). As I mentioned, I did a rough calculation, which I posted some months ago, showing that 5% of global fuel use and current sugar production are roughly similar is scale.

I am not a huge supporter of ethanol, but can't for the life of me see why poor small scale farmers in Thailand (where I live) growing sugar cane for ethanol makes people irate while growing the same sugar for Pepsi seems to be fine.

The thing is, it seems like one could make the exact same argument for, say, packaging of all kinds. In this case, it would be oil and/or wood products (?), as opposed to water. They use more resources - (?)- than say, bulk grains from bins at the co-op, - though, too, might be a wash, if people use plastic bags to weigh out unpackaged items.

I think this is right too. I sense that the big difference is that reducing waste allows us to continue "life as it is now". Since for some "life as it is now" seems to be the problem they are fighting against, reducing waste is a low priority - or in fact could be negative.

In this regard, ethanol, as a tiny part of a bridge to a new way of continuing with our lives, is the target of much more venom than piles of useless plastic bags.

I am not unsympathetic to either argument. I would love to see mankind transition to a completely different and better way of life, but I don't belive in throwing out what we have and just hoping too many people don't die on the way to an imagined salvation.

I do think we need to look in a quantitative and analytical way at the various waste with our system and find ways to reduce it. Improving the energy efficiency of civilization is one way to cope with the shrinking efficiency in energy production.

I do believe we are near peak oil and that there are no easy answers. However, I also believe that hard answers are still answers. I do think that trying different solutions and seeing which work is what is going to get us through this problem.

I have never seen a convincing argument that proves mankind couldn't, in theory, live just as happily on half the energy we use now. I expect the reality will be much more painful, but I don't thinkit is futile.

The section on cellulose ethanol is weak. Soy beans are more likely to be made into biodiesel. If (a very big if) cellulose ethanol ever becomes commercially viable, the raw material could be wood residues, garbage or native species with a low impact on soil such as switchgrass.

And scalability would still remain as a huge stopper. I am amazed that so many ignore this issue.

In my opinion, cheap oil has provided us the 'feeling' that everything is scalable, because the energy and versatility of oil can directly or indirectly accomplish almost anything. As oil becomes more scarce, the concept of 'impossible' might re-enter into normal conversations. When I was a kid (boy that makes me sound old...;), we used the word 'impossible' often. I rarely hear it anymore - its almost as 'bad' a word as 'atheist', 'communist' or 'reefer'.

This is a very astute observation. I am old enough to remember pessimism also, having Depression-era parents. 'Impossible' is not a term used by folks living in the virtual reality of modern-day North American suburbs where virtually nothing is real. There little is actually produced--not grains or meat; no wood products, paper or books; not minerals, steel, aluminum or manufactured goods. Mostly keystrokes, phone calls and full retail shelving. And a lot of easy optimism.

Burning biofuels impacts the nitrogen cycle. When you take dinitrogen from the atmosphere and convert it to n02 and n03 you are increasing the local concentration of fixed nitrogen in the air and soil. This has all kinds of negative impacts on the environemnt.


I am not a big fan of ethanol, but I do believe that there is another ethanol feedstock worthy of further study: sweet sorghum.

As you know, the EROI for ethanol from Brazilian sugar cane is far superior to that of ethanol from US maize (corn). I have seen EROI figures in the range of 3-4, but there has been so little research wrt sweet sorghum that I don't know how firm those figures may be; one would intuitively assume that the EROI falls somewhere between maize and sugar cane. This in turn suggests that the EROI for sweet sorghum would be at least 2-3 times higher than for maize. Given that maize ethanol is barely more than a break-even proposition, this certainly suggests that if we are going to do ethanol at all, sweet sorghum is worth a closer look.

An important reason why I think that sweet sorghum warrants further study is that its culture is very similar to that of maize, but perhaps not so input-intensive. In the Southern Appalachians, where I live, one sometimes sees maize and sweet sorghum growing adjacent to each other; to the uninitiated eyes, the crops look almost identical. The important difference is the absence of vulnerable ears of grain in the sweet sorghum crop. Massive inputs of fertilizer, water, and pesticides are required for maize plants to produce high yields of grain. In contrast, the sweet sorghum plants need only grow the stalk, which is far less vulnerable to pest damage and is less demanding of water and fertilizer. Because the crops are so similar (differing in their culture only at harvest), it would not be too difficult a transition for farmers to switch from growing maize to growing sweet sorghum. Harvesting at large scale would require different equipment; however, the harvesting equipment is inherently less complicated than that required to harvest maize.

One obvious disadvantage of sweet sorghum over maize is that it cannot be stored for a long period of time. The juice must be extracted from the stalks (traditionally done by a simple crank press, which could be scaled up to industrial levels) fairly soon after harvest. To make sorghum syrup, considerable energy is required to boil the juice down. More likely, the juice would not need to be concentrated to that level in order to become a suitable feedstock for a fermentation process. I am not certain how long such juice could be held in storage prior to being fermented, but there must be an optimal level.

Which raises the other obvious disadvantage: existing maize ethanol production facilities would require substantial retrofits to process sweet sorghum. I suspect that at least some of the installed distillation equipment would still work, but there might need to be some reconfiguration. The bigger problem would be the need to process the entire year's crop in a short period of time. Existing processing facilities have been built on the assumption of a year-round supply of maize feedstock. This might be an argument for concentrating the sweet sorghum juice to a higher level for storage, and then diluting it as needed. This in turn would then also require the construction of large storage tanks. All of this weighs against and reduces the EROI, but probably still results in a higher EROI than maize ethanol.

As I said, I'm not a fan of ethanol. But it does appear that political pressures are going to dictate that a substantial quantity of ethanol be produced, and produced from feedstocks grown in Midwestern farm states. Because sweet sorghum could be grown in those same farm states and promises a better EROI than maize ethanol, we ought to at least take a good look at it from a damage control perspective if for no other reason.

I am not a fan of biofuels in general, but you are correct - there are probably many things better for soil/water/energy balance than corn. What we need to do is look at the opportunity cost of the inputs of land, natural gas, diesel, water and fertilizer and see what the best outputs in terms of food and energy can be with least drawdown of limiting inputs. Sorghum may indeed have less opportunity 'cost' than corn. But who would make money selling sorghum seed to farmers? Right now, no one, which is why it won't be pursued. (yet)

Concentrating the juice is a waste of energy.  Given that shipping the crop any great distance is impractical, it would make more sense to ferment it immediately in large bladders (like methane digesters) and distill over time, slow-fermenting, high-tolerance yeasts would be a natural for this.  If contamination by e.g. acetobacter is a problem, the liquid could be treated with biocides after fermentation completed.

I'm having a discussion related to sorghum over at topix, so if you have any comments you may want to go there.

Sorghum sap is about 2% sugar so direct fermentation results in a low ethanol concentration, think near beer. This increases the energy cost for distillation. People have tried distilling directly in horizontal silos after first spraying the crop with sulfuric acid. They are then stuck at that point on how to distill. Concentrating the sugar up over the concentration in grape juice makes more sense. The method used to save energy when concentrating maple sap is to use reverse osmosis. To use a high tolerance yeast you want a high sugar concentration, otherwise regular yeast would be better. High tolernance yeasts usually need fairly strict temperature control so you can't be sloppy.

By the way, a friend of mine just joined Eprida, Danny Day's company. Thought their stuff might interest you.


WNC Observer,

Several friends of mine who live near Boone, NC are involved with making sorghum cane syrup. Last year, the processing of the syrup required almost an entire day to produce 2 batches using a wood fired outdoor cooker. Watching these proceedings, I got to thinking about the energy potential. To produce ethanol, the usual process requires limiting the sugar content of the fermentation liquid. There's an upper limit on how much sugar can be in the mix, as the alcohol content can only increase to the point at which the yeast is killed. I suspect that there is no need to cook the juice down to the syrup stage if one intends to put the resulting juice directly into a fermenter. I also think that you are probably correct that storage of the liquid for a long period before fermentation might be a problem. It might be possible to concentrate the juice somewhat to increase the sugar concentration to a more desirable level, then storing the resulting liquid for later input to the fermenter.

Another thought that came to mind is that there is a large volume of stalks remaining after the juice is removed. Since this biomass is already concentrated at the point where it is pressed, and most of the moisture is removed in the juice, the stalks might be another good energy source. I've been thinking about how to put that resource to use and may try an idea or two with this year's crop residue, which would otherwise be used as mulch. Of course, the stalks could also be used as fuel for the distillation process, much as is done in the production of ethanol from Brazilian sugar cane.

Perhaps better still, why separate the juice from the stalks if the goal is to produce ethanol? Grind the stalks and ferment them directly. Once the ethanol had been produced, the remaining slurry of stalks and DDGS might be a very good animal feed for cattle.

E. Swanson

Robert unimaginable scale has unimaginable environmental impact. To grow corn for all our gasoline needs would require 978,261 square miles. To replace our all crude petroleum would require 1,200,000 square miles of corn, or 1/3 of the United States of America. Put another way, all our corn converted to ethanol only accounts for 19% of our gasoline.

I am inclined to think that the most insidious environmental harm is the fact that ethanol is believed by the general public to be a "solution" to the oil problem such that nobody will need to make any changes to their lives other than to buy a flex-fuel car.

Bingo. That is the issue. And it's the problem that is being avoided like the plague by every political wanna-be. No politician will ever tell people they must change their lives for the worse, and that it will also cost them more to live less well. Ask that question at the next TV debate and watch them squirm!!

Clean (very low emissions) thermochemical processes like pyrolysis and gasification can be used for the creation of syngas (CO and H2) that can be combusted in place of natural gas. They don't require any water and to a great extent the feedstock supplies the fuel for continuing the thermal process.

According to the DOE, syngas can also be catalyzed or fermented into ethanol and other higher alcohols. The heat from the reaction can be captured to generate electricity. The yield is projected to be between 70-125 gallons per ton of feedstock based on pilot plant results.

Feedstock can be anything containing C-H-O including: fossil residues like petcoke; automobile waste like autofluff and tires; forestry wastes from the forest products industry; ag wastes like stover; decaying tree residues from wildfires and bug infestations; municipal solid waste; sludge; etc., etc.

This means that clean biofuel production creates a profit stream for solving a multitude of environmental problems and catastrophes.

These are the technologies that I am watching - not corn fermentation. I am not particularly enamored with enzymatic hydrolysis either but I am willing to support the research because the rate of technological development is much faster than ever before thanks to personal computers and communications.

I am inclined not to rule anything out under the circumstances.

I am amazed that the oil industry has not built any refineries in the U.S. for thirty years. Surely there have been some leaps in innovation that could be better deployed in a new facility rather than retrofitted to an old one.

I wrote the article on Peak Soil you refer to above (latest version at ), and there are some additional unsustainable, environmentally damaging aspects to growing any kind of plant for biofuels you didn't mention above:

1) Soil Biota

Soil creatures and fungi act as an immune system for plants against diseases, weeds, and insects – when this living community is harmed by agricultural chemicals and fertilizers, even more chemicals are needed in an increasing vicious cycle (Wolfe 2001).

2) Soil compaction

Plants and creatures underground need to drink, eat, and breathe just like we do. An ideal soil is half rock, and a quarter each water and air. When tractors plant and harvest, they crush the life out of the soil, as underground apartments collapse 9/11 style. The tracks left by tractors in the soil are the erosion route for half of the soil that washes or blows away (Wilhelm 2004).

3) Soils store more carbon than the atmosphere and vegetation

Soils contain 3.3 times the amount of carbon found in the atmosphere, and 4.5 times more carbon than is stored in all the Earth’s vegetation (Lal 2004). If we want to reduce global warming, storing carbon in the soil will be essential. But that will be hard to pull off, because Climate change could increase soil loss by 33% to 274%, depending on the region (O'Neal 2005). Intensive agriculture has already removed 20 to 50% of the original soil carbon, and some areas have lost 70%.

3) Continuous corn increases global warming by 71% (Powers 2005)

4) Destruction of CRP land, hardwood forests, wetlands, and range land to grow more biomass (and food) will reduce stored carbon & biodiversity

Farmers want to plant corn on highly-erodible, water protecting, or wildlife sustaining Conservation Reserve Program land. Farmers are paid not to grow crops on this land. But with high corn prices, farmers are now asking the Agricultural Department to release them from these contracts so they can plant corn on these low-producing, environmentally sensitive lands (Tomson 2007).

Population in the United States could reach over one billion people by 2100 (U.S. Census Bureau 2000), so what will happen is that we'll need more crop land and have to cut down bottomland forests and fill in wetlands to grow food, which will reduce stored carbon and biodiversity even further.

Deforestation of temperate hardwood forests, and conversion of range and wetlands to grow energy and food crops increases global warming. An average of 2.6 million acres of crop land were paved over or developed every year between 1982 and 2002 in the USA (NCRS 2004). The only new crop land is forest, range, or wetland.

5) Fertilizers increase global warming, acid rain, and eutrophication, but they provide no ecosystem services like organic matter (a.k.a. "waste" biomass), such as putting carbon back into the soil, increasing soil structure to let air and water to plant roots, preventing erosion, water retention, etc.

6) Rainforest destruction

Rainforest destruction is increasing global warming. Energy farming is playing a huge role in deforestion, reducing biodiversity, water and water quality, and increasing soil erosion. Fires to clear land for palm oil plantations are destroying one of the last great remaining rainforests in Borneo, spewing so much carbon that Indonesia is third behind the United States and China in releasing greenhouse gases. Orangutans, rhinos, tigers and thousands of other species may be driven extinct (Monbiot 2005). Borneo palm oil plantation lands have grown 2,500% since 1984 (Barta 2006). Soybeans cause even more erosion than corn and suffer from all the same sustainability issues. The Amazon is being destroyed by farmers growing soybeans for food (Wallace 2007) and fuel (Olmstead 2006).

7) Surface Albedo.

“How much the sun warms our climate depends on how much sunlight the land reflects (cooling us), versus how much it absorbs (heating us). A plausible 2% increase in the absorbed sunlight on a switch grass plantation could negate the climatic cooling benefit of the ethanol produced on it. We need to figure out now, not later, the full range of climatic consequences of growing cellulose crops” (Harte 2007).


Thanks for your excellent 'wide boundary' points.

3) Continuous corn increases global warming by 71%

Can you expand on what you mean?


I've excerpted bits from the Executive Summary, the last paragraph contains the answer to your query. Powers sees eutrophication as a more serious problem than the global warming and acidification components of her study. Corn after corn (C-C) would increase eutrophication by 189%.


Susan E. Powers. May 2005. Quantifying Cradle-to-Farm Gate Life-Cycle Impacts Associated with Fertilizer Used for Corn, Soybean, and Stover Production. NREL National Renewable Energy Laboratory.

Executive Summary

Fertilizers used to increase the yield of crops used for food or bio-based products can migrate through the environment and potentially cause adverse environmental impacts. Nitrogen fertilizers have a complex biogeochemical cycle. Through their transformations and partitioning among environmental compartments, they can contribute to eutrophication of surface waters at local and regional scales, groundwater degradation, acid rain, and climate change. Phosphate fertilizers have a simpler fate in the environment, although leaching of soluble and bound phosphorus is an important contributor to eutrophication.

Eutrophication is considered one of the most pervasive problems affecting water quality in the United States, especially in the Midwest where fertilizers are used extensively for agriculture. In the process of eutrophication, the presence of excess N and P nutrients allows over production of plant biomass in waterways. The eventual degradation of this biomass consumes oxygen resulting in hypoxic conditions (low oxygen concentrations) in the most severe cases of eutrophication. Fertilizer use on corn and soybean farms in the Midwest is considered one of the primary contributors to the growing hypoxic zone in the Gulf of Mexico. Through a combination of excessive nutrient loads and hydrodynamic conditions, a region along the coast of Louisiana that is approximately the size of the State of Massachusetts is considered ecologically dead most summers. This results in the death of species that are not sufficiently mobile and changes in biodiversity and food webs throughout the region as larger species migrate to other locations.

With an increase interest in the use of corn, soybeans and corn stover for bio-based products and fuels, it is important to understand the relative environmental benefits and deleterious impacts associated with this growing market.

The nutrient leaching model developed here was coupled with LCA data describing emission occurring during fertilizer manufacture and energy production and consumption, providing a cradle-to-farm gate life cycle inventory (LCI) for corn, soybeans and stover. Three separate scenarios were considered:

• Scenario 1: the base case, considered corn-soybean rotations (C-S) with conventional till and no stover collection;
• Scenario 2: C-S with no till and stover collection at a maximum rate allowable with acceptable erosion levels; and,
• Scenario 3: the same as 2 except for continuous corn (C-C) rather than C-S.

The LCI for each of these scenarios was quantified and used to determine eutrophication, acidification and global warming potentials for the three scenarios. Eutrophication was calculated for each year in a 13-year study period to incorporate variability with rainfall.

The results of this analysis show that the eutrophication potential for the base case (scenario 1) already exceeds acceptable limit. Total Nitrogen (TN) and Total Phosphate (TP) discharges from C-S lands also exceed the maximum loads defined by the proposed water quality standards in each of the 13 years of this study.

Changing the current C-S rotation to also harvest stover for biofuel production increases the eutrophication potential. With the assumptions used in this analysis, the C-Sstover scenario (2) results in a 21% increase in the eutrophication potential, while the C-C-stover scenario (3) almost tripled the total load of TN and TP (as equivalent NO3-N). In either case, the increased load is to a system that has already exceeded its assimilative capacity for nutrients. With the very high nitrogen demand in a C-C system, however, it is not likely that management practices could be sufficient to overcome the detrimental effects of eutrophication resulting from the high leaching rates.

The high nitrogen use in the C-C scenario also increases the use of fossil fuels for fertilizer production and associated emissions of species contributing to acid rain and global warming (GWP) potentials. The increase in acidification potential (+6% over the base case) is attributed to increases in NO production in soils with increased FN use and increased NOx from fossil fuel consumed to generate the increased energy necessary for fertilizer manufacture. Increases in the global warming potential (+71% over the base case, not including benefits of carbon sequestered in soil or crop) are attributed to methane emissions from natural gas used in FN manufacture and N2O emissions from nitrification and denitrification of the additional FN.

The take-home lesson appears to be that primary problem is leaching, and anything which can reduce it is all but certain to improve the outcome.

Terra preta is known to almost eliminate leaching even in the most severe environments.  If part of the stover is returned to the soil as charcoal, the excess nutrients could be captured and retained for later crops rather than leached out.  This would both reduce the required inputs (and all their impacts) and cut the effects downstream.

A plausible 2% increase in the absorbed sunlight on a switch grass plantation could negate the climatic cooling benefit of the ethanol produced on it.

This is implausible.  The albedo change creates a one-time effect; the heat balance is not altered afterward.  The displacement of fossil fuel creates a cumulative effect in the amount of carbon in the atmosphere, and its effect on the radiative balance.

This sort of error makes me question the accuracy of the quote, and Harte's bona fides if it is accurate.

Another thought comes to mind regarding corn. I have been reading "The Omnivore's Dilemma", which talks about how Big Ag has essentially created these perverse incentives whereby farmers will raise corn as fast as they can, get paid less than it cost them to grow it (and then get a gvmt check to make up the difference). All of the excess corn is then used to fatten cattle and make corn syrup and other nutriceuticals, which consumers then eat in increasing quantities to the detriment of public health.

The corn ethanol thing really just got going again a few years ago. The increased corn prices are hugely popular with farmers who previously were just struggling to get by, and of course it is popular with Big Ag.

If farmers formed a OCEF (Organization of corn exporting farms) they could set a price floor for corn below which it couldn't be sold. Hell, if individual farmers in an area would just meet and agree to not sell their crop at a loss, they could force buyers to pay a reasonable amount.

That is essentially what Orderly Marketing Agreements are.

Farmers are pretty much the classic example of suppliers who can't maintain a cartel. There are too many of them, and the advantage to free-riders is too big.

environmental benefits of using ethanol as fuel?

Perhaps if it was done right (and assuming cellulosic ethanol works)

the grasses took in more carbon dioxide from the atmosphere than was released from the fuel used to grow and process them. The carbon dioxide removed - around a third of a tonne per hectare per year - was taken up by the roots and so remained in the soil after the harvest. This means that the greenhouse gas savings from wild-grass ethanol could be up to 16 times as great as those from corn (Science, DOI: 10.1126/science.1133306).

Hill's work also suggests that wild grass could be farmed more efficiently in mixed species plots, mimicking the make-up of natural prairie. When his group combined eight species of grass in a single plot, yields were more than 150 per cent higher than from grass monocultures. In 16-species plots, the improvement was 238 per cent.

Such diverse mixes provide better havens for wildlife. In Wisconsin, Sample has studied field-sized plots of mixed grasses of the type that would be suitable for biofuel farming. He found that a typical plot hosted three threatened bird species, while the average for corn was less than one species per plot. Harvesting the grass should not wipe out these gains in biodiversity, because it would have a similar effect to the fires that sweep through natural prairies most years. It all suggests that America's prairies, which now cover just 1 per cent of their original area, could be partially restored by biofuel farming, Hill says.
(subscription required)

Article in Science:
Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass

Across their full life cycles, biofuels can be carbon neutral [no net effect on atmospheric CO2 and other greenhouse gases (GHG)], carbon negative (net reduction in GHG), or carbon sources (net increase in GHG), depending on both how much CO2 and other greenhouse gases, expressed as CO2 equivalents, are removed from or released into the atmosphere during crop growth and how much fossil CO2 is released in biofuel production. Both corn ethanol and soybean biodiesel are net carbon sources but do have 12% and 41% lower net GHG emissions, respectively, than combustion of the gasoline and diesel they displace (14). In contrast, LIHD biofuels are carbon negative, leading to net sequestration of atmospheric CO2 across the full life cycle of biofuel production and combustion (table S3). LIHD biomass removed and sequestered more atmospheric CO2 than was released from fossil fuel combustion during agriculture, transportation, and processing (0.32 Mg ha–1 year–1 of CO2), with net life cycle sequestration of 4.1 Mg ha–1 year–1 of CO2 for the first decade and an estimated 2.7 to 3 Mg ha–1 year–1 for subsequent decades. GHG reductions from use of LIHD biofuels in lieu of gasoline and diesel fuel are from 6 to 16 times greater than those from use of corn grain ethanol and soybean biodiesel in lieu of fossil fuels

Harvesting prarie grass does not have the same effect as a fire burning the grass would. Burning of grasses cleans out old growth so that new grasses can grow like harvesting does, but it also allows some species' seeds to germinate which harvesting would not.

- Scott
"Try sour grapes; you might like them."

OFF TOPIC WARNING...Robert, a request, we need your technical help since your posting with us for a bit..:-)

Canadian Tar Sands, recently much discussion about THAI (Toe to Heel Air Injection) for in situ extraction, by Petrobank, Canadian firm....what can you tell us about prospective validity....we need an unbiased view, and a great petro technician, so can we draft you on this one?

Remember, we are only one cubic mile from freedom :-)

This is the article (posted by me) that raised questions.

Not sure if this falls under "Ethanol and the Environment". It's worth pointing out that the energy density of EtOH is only 70% that of gasoline. You can get some of that back by taking advantage of the higher octane, but not all of it. This only adds to EtOH's VOC -> ozone problem. It is an oxygenate and has no sulfur, which helps with PM formation, at least directly (one has to be careful about PM metrics).

The flame temperature of EtOH is a little lower than that for gasoline, which should lead to lower NOx, although with the heavy EGR modern engines use it's not clear that the reduction is significant. In any case, that wouldn't make up for the higher VOC emissions as far as smog is concerned, and in urban areas (which are all VOC limited) would only compound the problem.

It seems that using the term ethanol, rather than specifying corn-based ethanol (when that is the case) is sloppy and leads to inaccuracies.

If you were to replace several of the uses of the term ethanol with "all ethanol", they would clearly be wrong.

Sugar cane-based ethanol does appear to have a far better energy balance than corn-based ethanol. Sugar cane is not typically irrigated, so the water issue doesn't seem to directly apply.

Khon Kaen Sugar is a publicly listed company in Thailand that discloses a lot of data on the costs and process of their refining. This could be useful. Try the annual report and their investor presentations. The presentations used to be easy to find on the site, but just now i didn't see the link. I can send one if you can't find it.

Scalability is obviously an issue. But I think Nate's attack on both scalability and searching for replacements is a bit inconsistent. If you are looking for a replacement, scalability is a huge problem. If you are talking about providing 5% of total liquid fuels over a timeframe of about ten years as a transition to better ways of doing business, scalability is much less crucial.

I once calculated that we could get a few percent of total fuels just by cutting sugar consumption in half.

I don't think ethanol will ever be a major part of the energy picture. Neither do I think it is a permanent solution. It will serve a small and temporary role. I don't think it makes sense to curse a silver BB because it is not a magic wand.

It does seem the objective of the piece you are writing is not to oppose the ridiculous US ethanol policy, but to inform people about the topic. The title of the ethanol FAQ certainly implies that is not a strictly US-centric piece.

So, I would suggest that you either state up front that the piece is about US corn-based ethanol, or make the piece broader than just US corn-based ethanol.

I should add the list of studies below and note that they give EROEI of 8-10:1 for sugar cane-based ethanol. Following this, their assessment of ethanol's impact on climate is massively more positive than the corn-based calculations in your article.

I am aware that the sugar cane energy balance studies are not nearly as complete as those done for corn. I have no reason to believe that these numbers are the right ones. However, it does seem that energy balance and climate impacts for sugar cane-based ethanol could be substantially better. I don't think a balanced overview can ignore this information.

1) FO Licht presentation to METI,

2) IEA Automotive Fuels for the Future

3) IEA: Biofuels for Transport

4) Worldwatch Institute & Government of Germany: Biofuels for Transport (Link to register – study is free)

5) Potential for Biofuels for Transport in Developing Countries

Hi Robert,

Thanks for this tremendous effort, for sticking with it - and for asking for feedback.

1) When you start off talking about “benefits…as well as negative environmental consequences”, as I read this, I’m waiting for the shoe to drop, perhaps in the form of a question like “Do the benefits outweigh the negative consequences?”

Because you seem to contrast the two (benefits and consequences). Perhaps another sentence or two that either states your position – and/or… asks something like “How do we weigh one against the other?” , i.e. lays out your criteria for answering the question. (Just a thought.)

2) re: “Because of ethanol's marginal energy balance, there is a marginal reduction in greenhouse gas emissions per distance driven. Researchers have also found that ethanol produces less carbon monoxide when it is burned in an internal combustion engine.”

Well, in my role as naïve reader (and thanks for your patience)…I’d enjoy just a tad more explanation here.

Q: A “marginal reduction” – when… ethanol is blended with gasoline? When ethanol is used as a replacement (by what percentage?) in gasoline? (Any other qualifiers? ie., “distance driven” – regardless of vehicle type, size, etc.?)

Q: re: “less carbon monoxide” - less than what? (This sentence just seems to lack a reference.) BTW, are you referring to gasoline and diesel and NG when used as ICE FF and contrasting them w. ethanol use? Or…?

3) I like Nate's comment back at, where he starts esp. the "big picture" idea in his question “What would be the best use for all that natural gas, land and diesel?”

“What NEEDS to be being debated is not the absolute energy yield but its comparison to what its replacing. The net energy of gasoline is in the neighborhood of 8:1, vs ethanol at .2:1 - it is an order of magnitude less - the more we replace of substance A with substance B, the less amount of energy available to do work for society. In effect, the energy balance should be used as a societal energy budgeting tool. What would be the best use for all that natural gas, land, and diesel? Corn is probably near the worst idea.”

And I also like his paragraph in this thread where he says:
“But it is natural to want to find a 'replacement' for something, in fact we are conditioned to do so. In the end, changing our way of life and moving away from the internal combustion engine will serve us much better than scaling up land, material, soil and water inputs to create an inferior fuel. But it will take time for this message to sink in, because its a very difficult one (at first) to accept.”

Perhaps you can take these as a cue, or re-write (taking out the “buts”) – i.e., do you agree w.his assessment that ethanol is “an inferior fuel”?

If so, perhaps this might help in forming a one or two sentence Q or statement along the lines of: “When we look at environmental costs, we need to keep in mind that the decline in availability of oil means we have a limited amount of time to put in place the kinds of infrastructure that can use electricity supplied by renewable energy technologies, such as wind and solar. To lose sight of this time window is to risk spending our endowments of natural gas, water and topsoil on the wrong things.” (Not that I’m saying this well, just to give an example.)

Or, “The ‘big picture’ of environmental costs is the risk of degrading our ecosystem…”

4) When you quote an article at length, it might be nice to sum it up in a sentence or two (of your own words) at the end, so as to add some continuity for the reader.

5) A small stylistic point for readability – perhaps just list out the “positives” and “negatives” and then label each one before you talk about it. eg. “We have X number of benefits the industry itself considers positive, and, on the other hand, we have the ten following negative environmental consequences: A, B, C, D…” (Do the positive outweigh the negatives for large-scale uses?)

6) Jack’s point about specifying the types/sources of ethanol seems important and

7) Alice’s many points seem crucial - and fascinating. Many thanks, Alice. I like the way these are classified as being true for growing any kind of plant for biofuels.

(Robert, does this pose a challenge to evaluating the benefits of your other biofuels project?)

If so, then perhaps it would be a good idea to separate the “environmental impacts” Q into sections, such as “negative impacts from any plant source for biofuels production” and “additional negative impacts specific to corn as a plant source”.

8) Although looking at Alan’s quotes on the non-row crop farming of plants for biofuels…it might be nice to have some direct dialog between these two on this topic. If we could get more into it.

9) The point about water is so important. Nate’s “rather drink than drive” – exactly. “have to”, in fact. (This might be a good place to talk about the fact that humans need “the environment”.) There’s a lot to be said on this topic, and all of it seems really important.

This would be a lot more work. OTOH, it seems like you’d really have something really useful to many people.

10) Anewland’s point on scalability seems like a very important one in the “big picture” – and its succinct:, like “Okay, what is our environment? Well, in the US, it’s a land mass of X, …”

11)PS and as an aside, someone brought up in the other comments section, the idea of corn subsidies for ethanol v. oil co subsidies. I just wondered if there was a reasonable way to actually compare them in money terms. Also, this does seem to be another red herring, still, it’s one that is likely to come up again, so wonder if it might be good to address it early on.

I'd like to simply post a link to show Brazil's ethanol miracle has a major downside -,,2029908,00.html

This energy efficiency (EROI) claim is based on essentially free (read SLAVE) labor - such a surprise that this could happen, with ownership by such paragons as Cargill, ADM, and George Soros and Bill Gates, I know

this article would cause any ethical person to reconsider - even without all the worry that the extended loss of the Amazon Rainforest may soon reach (if it hasn't already)a tipping point where the trees all die and the self-propagating weather of the region ceases - and this likely will in turn disrupt global weather patterns -
Nice little side effect of this "renewable"

Yes, i know sugar doesn't grow well in ex RF - but you have to realize that land expropriated for sugar pushes other uses (like subsistence farming/clearing)outward into the RF

Some of these darned poor just refuse to die quietly!
(PLEASE-this is meant as a brutal but true reflection of what the corporations consider good business -not my opinion)