Biofuels: Bring back the Prairie

At risk of annoying everyone else by stealing too much real estate here, I couldn't resist drawing attention to a very interesting paper in Science tonight by Tilman et al. Here's the abstract:

Biofuels derived from low-input high-diversity (LIHD) mixtures of native grassland perennials can provide more usable energy, greater greenhouse gas reductions, and less agrichemical pollution per hectare than can corn grain ethanol or soybean biodiesel. High-diversity grasslands had increasingly higher bioenergy yields that were 238% greater than monoculture yields after a decade. LIHD biofuels are carbon negative because net ecosystem carbon dioxide sequestration (4.4 megagram hectare-1 year-1 of carbon dioxide in soil and roots) exceeds fossil carbon dioxide release during biofuel production (0.32 megagram hectare-1 year-1). Moreover, LIHD biofuels can be produced on agriculturally degraded lands and thus need to neither displace food production nor cause loss of biodiversity via habitat destruction.
So basically, we should return much of the Midwest to prairie and then mow it regularly to make biofuels!

A few other fair-use snippets from the full paper (which is behind a paywall alas):

We performed an experiment on agriculturally degraded and abandoned nitrogen-poor sandy soil. We determined bioenergy production and ecosystem carbon sequestration in 152 plots, planted in 1994, containing various combinations of 1, 2, 4, 8, or 16 perennial herbaceous grassland species (table S1) (10). Species composition of each plot was determined by random draw from a pool of species. Plots were unfertilized, irrigated only during establishment, and otherwise grown with low inputs (10). The 16-species plots are the highest diversity, or the LIHD (low-input, high-diversity), treatment. All plots were burned in early spring to remove aboveground biomass before growth began. Soil samples, collected before planting in 1994 and again in 2004, determined carbon sequestration in soil. Plots were sampled annually from 1996 to 2005 for aboveground biomass production.

The gross bioenergy yield from LIHD plots was 68.1 GJ ha-1 year-1. Fossil energy needed for biomass production, harvest, and transport to a biofuel production facility was estimated at 4.0 GJ ha-1 year-1 (table S2). Different biofuel production methods capture different proportions of bioenergy in deliverable, usable forms (Fig. 2) (10). Cocombustion of degraded land LIHD biomass with coal in existing coal-fired electric generation facilities would provide a net gain of about 18.1 GJ ha-1 as electricity (11). Converting LIHD biomass into cellulosic ethanol and electricity is estimated to net 17.8 GJ ha-1 (12). Conversion into gasoline and diesel synfuels and electricity via integrated gasification and combined cycle technology with Fischer-Tropsch hydrocarbon synthesis (IGCC-FT) is estimated to net 28.4 GJ ha-1 (10, 13).

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

To put this in context, here's global land use:

Major classes of global land use shown as individual trend lines. Source: FAO.

If the 1.4 billion hectares of ag land were all LIHD plantations sequestering about 3 tonnes net of CO2/ha/year, which is around 0.8 tonnes of carbon, then we would sequester an additional 1.1 gigatons of C. This should be compared with the 8 and rising gigatons of C emitted from fossil fuel burning. Obviously, we couldn't do this with all ag land either. Thus the contribution to offsetting global carbon emissions from this could only be modest. However, the net energy story sounds like it might be quite strong, so this may be a useful wedge to both our energy and climate problems (assuming that deriving fuel from a diverse feedstock can be made commercially practicable).

It occurs to me that there is even a "device" already in existence that humans can employ that is "designed" to automatically harvest the excess biomass from those natural swards and that automatically recycles the unusable material directly on-site.

It is called a cow (or sheep/goat/camelid) and competes with other herbivores, such as insects. I wonder what the energetics of that system is? In any case, I suspect that we will be employing more ruminants in that extensive capacity rather than in the intensive capacity, where they are housed and fed high energy feeds.

Not only that, but oxen (and goats) are good for pulling wagons.  Byproducts include meat, milk, leather, and fiber.
Cows (and sheep, etc) are huge emitters of methane - 14% of global release. Not good considering that methane has 20 times the "greenhousing" effect of CO2

12:40 01Dec2005 RTRS-Cure for cow flatulence cooked up by UK scientists

    LONDON, Dec 1 (Reuters) - Cows belching and breaking wind cause methane pollution but British scientists say they have developed a diet to make pastures smell like roses -- almost.
    "In some experiments we get a 70 percent decrease (in methane emissions), which is quite staggering," biochemist John Wallace told Reuters in a telephone interview.
    Wallace, leader of the microbial biochemistry group at the Rowett Research Institute in Aberdeen, said the secret to sweeter-smelling cows is a food additive based on fumaric acid, a naturally occurring chemical essential to respiration of animal and vegetable tissues.
    A 12-month commercial and scientific evaluation of the additive has just begun, but he said if it proves successful it could be a boon to cutting down on greehouse gas emissions.
    "In total around 14 percent of global methane comes from the guts of farm animals. It is worth doing something about," Wallace said. Other big sources of methane are landfills, coalmines, rice paddies and bogs.
    Scientists in Australia and New Zealand have also been working to develop similar products amid growing concern about greenhouse gas emissions from cattle and sheep.
    In New Zealand the government in 2003 proposed a flatulence tax, with methane emitted by farm animals responsible for more than half the country's greenhouse gases. The plan was ultimately withdrawn after widespread protests.
    "We've had more success than they (scientists in Australia and New Zealand) have. Everyone has been trying different methods. We just got lucky," Wallace said.
 ((Reporting by Nigel Hunt, editing by Michael Roddy; email:; RM:; +44 (0)20 7542 8421)

But putting cows out in pastures won't necessarily increase the total number contributing methane. If this change in values was accompanied by a move to eat less meat then we could empty the feed lots.
i think you should be working on a devise (ie insert nozzle) to capture that methane at its source
I'd always read that the methane production of cattle was due mostly to mankind meddling in their diet.  They were not designed to handle a diet of potatoes, sugar beets, corn and grain, they were designed for grass.  We feed them the other stuff to fatten them up for market.   If I remember correctly the standard feedlot diet disagrees with them so much, they have to have a constant supply of anti-gas medication added to their feed (bicarbonate of soda?).

I know that happens to me
Above was a bit "tongue in cheek"; I was really thinking that the processes of nature are optimized for energy collection and transfer over both distance (microns to kilometers) and time scales (days to seasons to years) in the ecosystem through coevolution of all the components, whether plants, soil microbes or herbivores (microbes to insects to ruminants). Anything we humans do that perturbs such systems likely markedly decreases that the system's energy capture and transfer if we reduce or stop our inputs - tillage, fertilzer, irrigation, monoculture and so on.

Wildlife biologist Allan Savory, Holistic Management International, recognized this many years ago in African game-forage ecosystems and wrote a book on the principles called Holistic Resource Management. As I recall, he found that removing one of the components, such as excess game offtake, reduced the forage production and hence energy production in systems where coevolution had occurred. One of the signals was a decrease in successional complexity, which is exactly what we do when we impose a monoculture.

An important aspect of decreasing successional complexity that is often overlooked is the decrease in system resilience. One aspect is the increased spread of infectious agents. Plants have infectious diseases just as we do and packing plants together in a monoculture provides great opportunity for emergence and spread of these agents. The use of particular new species for monoculture cultivation for biomass production puts the system at risk because, compared to the other plant species under extensive cultivation, we likely know very little about the diseases of the new species in such systems. Even with the knowledge we have developed over many years of research, we still constantly fight such diseases in the species we have under cultivation.

An example is asian soybean rust

"I was really thinking that the processes of nature are optimized for energy collection and transfer over both distance (microns to kilometers) and time scales"

This opinnion, unless a humoristic entry, would be greatly ignorant of how evolution works. Plants produce hard cellulose walls and any number of nasty chemistry for a simple purpose: they are trying to make it harder for herbivors to eat and to digest them. There is, of course, a co-evolution going on between plants and herbivors. By large the plants are winning.  We are the perfect example of just that: we have essentially given up to compete on that level of the game and are have resolved to eating the herbivors that haven't quit the plant battle, yet.

Absolute energy efficiency is, in most eco-systems, not a problem or we would have seen plants with photochemical mechanisms far superior to photosynthesis. After all... a silicon solar cell beats photosynthesis by a factor of 20! But it seems to be harder for evolution to switch from the local extremum that photosynthesis represents to a totally different chemical electron transfer and storage mechnism than to keep improving other survival mechanisms (like toxins). As long as everyone competes using the same photosynthesis engine, there is very little selection pressure from that side.

As a result... we can not expect to get much more energy out of plants than we already are (except that we don't use most of it efficiently). We could get two orders of magnitude more energy out of solar cells, though.

"This opinnion, unless a humoristic entry, would be greatly ignorant of how evolution works. Plants produce hard cellulose walls and any number of nasty chemistry for a simple purpose: they are trying to make it harder for herbivors to eat and to digest them."

Talk about the pot calling the kettle black. The suggestion that there is some purpose in the way evolution works, that evolution did something in order to accomplish something else, suggests a fundamental misunderstanding of the process.

The first paragraph in this comment is the funniest thing I've read on this site in a long time.

Yes, there is a co-evolution going on between plants and herbivores. Looked at the level of populations, rather than individuals, there is some give and take, but the relationship is largely a symbiotic one. Herbivores distribute seeds, either by their intestinal tract, or by their coats. The same goes for pollen. That act would be a good trade from the grass' perspective, but there's another important benefit that the herbivore brings: The creation and maintenance of habitat.

Perennial grasses (and clovers) that co-evolve with herbivores must be able to withstand being cropped every couple of years. Plants that can't deal with this cropping as well, can't compete in such an environment. This fact is why the plains were covered in perennial grasses (and clovers) but not trees. If it weren't for the herbivores, trees would have taken over much more of the plains. If the plants are winning, they are winning with the help of the herbivores.

But your last two paragraphs are just about bang on. I won't quibble the details because it would muddy an very insightful point.

Perennial grasses (and clovers) that co-evolve with herbivores must be able to withstand being cropped every couple of years

take it even further- perennial grasses and clovers depend on being cropped regularly for their survival.  At least in the midwest, if a field is not regularly cut down by burning, mowing or herbivorous chewing, it will be replaced by forest in short order.  This is part of the natural symbiosis between grazing animals and perennial grasses.  

If it weren't for the herbivores, trees would have taken over much more of the plains.

I think you're forgetting the important role of prairie fires.

No need to worry about peak oil

Lauri Venøy wants to use the product created from liposuction to develop bio-diesel.

Bio-diesel can be produced from plant oils and/or animal fat, and the Norwegian sees the scheme as a renewable energy source, newspaper Dagens Nærinsgliv reports.

"Maybe we should urge people to eat more so we can create more raw material for fuel," Venøy said.

Too late. The Brad Pitt character in 'Fight Club' has that territory locked up. Tyler Durden crafts the stuff into lavender scented 'body' soap.
I heard the story on this article listening to NPR last night and had the same thought as Stuart;

"So basically, we should return much of the Midwest to prairie and then mow it regularly to make biofuels!"

While the image is certainly amusing, something in it disturbs me and I can't quite put my finger on what it is. Perhaps it is the notion that we turn 1/3 of the country into the equivalent of a lawn. (Disclaimer: my front lawn is "xeriscaped")

So us hippie environmentalists have been right all along? It's another beautiful day in Paradise.

Here is an old idea...

The Buffalo Commons as a possible future

These guys have been trying to save and restore what's left of the tallgrass. Some folks even walk railroad right of ways to collect seeds, cuz there are still small patches here and there.

Quick comment about harvesting Prairies.

Prairies have net carbon gain when they are not harvested and not heavily grazed.  Soil building due to prairies (net carbon gain) was a result of an intact ecosystem with migrating grazing animals.  Heavy grazing and/or mowing tends to destroy prairies.

My knowledge of this is based on my botany degree and my wife's work doing prairie remnant surveys for the U.S. government in Iowa.

No such thing as a free lunch, even with Prairies.

I concur.

That said, I'm sure you and your wife would agree that 100 million acres of prairie planted with a nitrogen fixing perennial DEC (switchgrass or my preference canabis sativa) would be a far cry and considerably better for the prairie than 100 million acres of environmentally destructive, fossil fuel and water intensive GMO corn or GMO soy that grows at present would you not?

I am neither pro or con on this issue.  Too complex for simple answers.

I like the Prairie and see great value in wild and undisturbed lands.  We need more of them and need to hold onto what is left.

However,  I have also seen great positives made with no or low tillage crops used for food.  Done right these crops can still have a net carbon gain to the soil due to root mass and residual leaf/stem.  A farm I hunt switched from conventional to no till 2 years ago and the change in the soil structure, for the positive, is significant.  Soil is now softer, more friable, better water holding capacity and more above ground structure in winter that holds the soil.

The key here is that many conventional, including some GM, crops are adapted to high intensive cropping via breeding selection.  Not all agriculture is bad for the environment.  Marrying more sustainable agriculture practices to them is what should be doing first, not try and re-constitute Prairie communities which are immensely complex.

A pretty stand of planted Big Bluestem, Indian Grass, Compass plant, Lead plant and Purple Cone Flower does not a Prairie make.  Prairies are symbiotic interactions of plant, animal, insect and bacterial populations and take years to reproduce.  We destroyed them easily in a few years, unfortunately we can not remake them in the same time frame.

It is always a matter of scale when discussing biofuels. "100 of millions of acres of prairie" converted to ethanol production would only contribute a small fraction of our gasoline needs and disable ecosystems, communities, and food-favoring humans.

6 tons of switchgrass / acre / year - normal Iowa switchgrass acre
70 gallons of ethanol / ton - current process efficiency
= 420 gallons of ethanol / year / acre
= 1.15 gallons of ethanol / day / acre
= 42,086,956.52 acres needed / day
= 65,760.86 square miles harvested & processed / day

Which means, to meet 10% of current gasoline energy demands, someone would need to harvest and process enough switchgrass equal to the entire state of Illinois every day.

A billion tons of biomass is produced on the continent annually and DECs such as canabis sativa can easily produce 10+ tons per acre under optimal growing conditions.

Our scientists work on the NREL theoretical of 100 gallon yield per ton of gasified biomass, however, an ethanol catalyst at >65% selectivity should produce 169 gallons per ton per the syntec process.

Yes, there are technical hurdles.

Yes, there are known unknowns.

However, your assumption that "100 (sic) of millions of acres of prairie converted to ethanol production would only contribute a small fraction of our gasoline needs and disable ecosystems, communities, and food-favoring humans." is to be polite... wrong.

Your scientists are wasting someone's money.

Land will be used to produce solid fuel for space heating, water heating and some electricity, because the energy return when used as a solid fuel is already between 10:1 and 20:1, and is as likely to improve as is any liquid fuel process.  Moreover the technology to convert perenniel grass, such as switchgrass, into pellets or bricks, is inexpensive.  Production and distribution are relatively low tech.

Space heating is as fervently demanded as is transport fuel.
People will give up driving alone, before they give up living in single family units.  The land suitable for 'energy' crops is overwhelmingly in regions that experience winter.  

The space heating crisis looms, as natural gas production approaches the production cliff, while the more gradual downslope of liquid fuel production has a mountain of easily overcome consumption inefficiencies to mitigate the effect of declining supply.

At the farmgate, the buyer for the liquid fuel manufacter will not compete with the buyer for the solid fuel manufacturer.

You folks are pissing away good money.  But party on, while it lasts.

I suggest you rethink this gem, 'space heating is as fervently demanded as is transport fuel.'

As for our catalysis research...  your opinion is your own, however, the feedstock for syngas as you know, is virtually any carbonaceous material i.e. coal, NatGas, MSW, biogas and of course biomass in the form of agricultural residue, green waste, forestry residue etc. that can or is currently economically harvested or captured.

In many instances, these renewable wastes are a cost negative feedstock from some other industry i.e. manure from agriculture, that must be dealt with for a myriad of reasons.

As Peak Oil is a LTF crisis (not a space heating crisis) one need not be a rocket scientist to visualize the potential economic and environmental impact a LTF production path utilizing said feedstocks would have.

Dream on.  Peak oil is part of a larger energy crisis, of which the most immediate impact will be felt by those millions depending on natural gas to keep their water pipes from freezing.  We were discussing the use of the prairie to source fuel.  Your industry will not be able to compete for supply of the perrenial grasses suited to this environment because you aren't remotely close on the energy profit front.  Nor is the demand for transport fuel going to be any more intense than the demand for heating fuel.

As for the use of manure, go ahead, though over time the concentrations of it are likely to be fewer as the oil and gas dependent meat and egg manufacturing factories close their doors.

The fact is yours is an industry dependent of the public dole and it always will be.

You appear to be claiming nitrogen fixation for switchgrass and canabis. Neither plants is a legume and both require complete NPK fertilizers for sustained yields.
That's not what the paper is saying. They annually harvested and got carbon sequestration in the soil.
But the harvest is pretty meager.

Taking their figures of 68.1 GJ/ha and dividing by a reasonable figure of 17.4 GJ/MT, we get a yield of 3.91 MT/ha or 1.75 short tons/acre.  Contrast this with ~2.5 short tons/acre of corn stover alone from the average field, and another 4.2 short tons of grain.

Even if we radically increase efficiency of use (ala Sustainability), we're not going to be able to support "American Dream" lifestyles on harvests that slim.

Presumably this reflects their experimental conditions of no inputs and degraded soils versus an "average field" which is probably pretty degraded too but has a lot of inputs.

Historically, with energy inputs very cheap, it's been the case that it was more profitable for farmers to use a lot of inputs and gain more ouput.  Hence we have a farming system with very low EROEI but high yields/acre.  These guys are pointing out that a low input system with a broad species mix has significantly higher EROEI (though we can't tell exactly what the number is).  The question is under what circumstances would their approach be more profitable?

That does make a difference.  However, if recycling 1 GJ of fuel as input to a Haber plant for extra nitrogen yields 10 GJ of additional growth, increasing inputs does look rather profitable.

I took a look at possibilities like that in Starting the cycle, and found that corn stover could supply both all the nitrogen and all the diesel required to grow a crop of corn (with plenty left over).

Energy Profit Ratio (round) figures:

Before use of fuel : 17

Cocombustion with coal : 4.5

Convertion to Cellulosic ethanol and electricity : 4.5

Fischer-Tropsch : 7

Compare to:

Sugarcane ethanol in Brasil : 8

Corn ethanol in USA : 1.3 (optimistic)

This method is not better than at least one mono-culture. Still if this experiment was performed on extra-tropic land the numbers are quite good.

Another thing to note is that using the fuel in internal combustion engines will cut the profit at least in half.

I don't think these calculations are right because they don't include the energy input at the biofuels plant (which isn't stated in the paper so I don't think it's possible to calculate the EROEI from the numbers they gave).
I assumed they were, so much the worse...
Well... a barrel of oil contains 6.1 GJ. If a hectare of LIHD plants yields 28.4 GJ, this means 4.6 barrel/hectare. We are using 31 GB/year which translates go 6.7 billion hectares, or close to 5 times the total areable land. Even replacing modest 10% of oil will require half of the total areable land.

Now as I see it the plan is to cultivate permanent pastures for biofuel production, which makes much more sense, but yet the limit gets ot ~50% of oil usage if we convert all pastures to biofuels (not even remotely realistic IMO).

You just repeated a trivial argument for the upper limits of biofuels that nobody wants to listen to. Every time it is brought up I can hear the choir put their thumbs in their ears and sing "Lalalalalalalalala - I can't hear you - Lalalalalalala!"

Biofuels are mostly a technology (and a farm porking scheme) looking for an application. They will not change the overall scale of the problem by much. But what they do extremely effectively is to syphon off large scale investments into real  solutions like engine efficiency, wind and solar energy and combust them to a political smoke-screen.

"Biofuels are mostly a technology (and a farm porking scheme) looking for an application. They will not change the overall scale of the problem by much." - this statement is absolutely ridiculous.

I suggest you try again using thermo-chemical conversion yields of 100 gallons of biofuel per ton of gasified biomass at 10 tons per acre on 100 million acres.

That still only gets you halfway to replacement of gasoline for the USA, and a much smaller fraction of the way to replacing all transport fuels.

I get the feeling that you view every problem as a nail because the only tool you have is a hammer.

This can be summed up in this basic attitude: "N

"Nothing will change!!  We will continue on as usual, just the source of our fuel will change.  Our cities will not change. Our suburbs will not change. We will continue to ignore what is happening to our farmlands, our prairies, our wilderness areas. We will not change our driving habits. We will not change our vehicles. We will not walk. We will not ride a bicycle. And above all, we will not and shall not be inconvenienced. And this will all be free with no consequences for us, our children, our grandchildren. Life will and must go on before.  Our lifestyle will not change, because to deprive us of our lifestyle is like depriving us of oxygen."

Oh, and I almost forgot.  Ethanol will be a free lunch and will have absolutely no effect on our food prices, especially meat. We will chow down and remain fat just as we already have.

And if all this does not come to pass, we will be outraged and we will demand lower food prices or we will fire our politicians.

"Ethanol will be a free lunch and will have absolutely no effect on our food prices, especially meat. We will chow down and remain fat just as we already have."

Yet another shining example of just how far removed Tstreet is from those actually invovled in the biofuel industry - whata surprise!

switch grass would be much better at sequestering co2 if it was just planted and left alone (let the deer and antelope play)    conservation has a better chance of eliminating our "dependency" on foriegn oil than any "solution" (ie biofuel) i have seen from the politicians imo
Ted Turner is silently making progress on the Popper's idea of returning the midwest to a buffalo commons.  It is possible that our mismanaged farm programs, aquifer depletion, climate change, and ethanol funding will ensure this happens eventually. For now, I'm very concerned about the food supply.  Wheat shortages because of the drought in Australia are causing increases in our US exports to Asia.  My concern is that in '07 people will be unexpectedly faced with greatly increased food and energy prices.  Then, demand destruction can begin.  
The authors tried switchgrass too:

Switchgrass (Panicum virgatum), which is being developed as a perennial bioenergy crop, was included in our experiment. Switchgrass monocultures can be highly productive on fertile soils, especially with application of pesticides and fertilizer (20, 21). However, on our infertile soils, switchgrass monoculture bioenergy [23.0 ± 2.4 GJ ha-1 year-1 (mean ± SE)] was indistinguishable from mean bioenergy of monocultures of all other species (22.7 ± 2.7 GJ ha-1 year-1) and yielded just a third of the energy of LIHD plots (10).


Right on the money with this citation.  Switchgrass will not (in my opinion) be the savior for bioenergy.

My prediction of what has to happen.

  1. Optimize, incentivize, and use sustainable agriculture practices.
  2. Return as much useful biological waste to the soil as possible for fertilizer.
  3. Rely heavily on crop rotation with legumes to capture Nitrogen.
  4. Use conventional crops that have established high productivity and we know how to manage them.
  5.  Feed all into bioreactors and some ethanol/biodiesel plants.
  6.  Close the loop on running these plants using wind, solar and stover waste, eliminating almost all fossil fuels for operations like this
  7.  reduce total fuel/energy needs down to what can be produced renewably.

That last one is the hardest.  We might not even try that one until we have to and can see how difficult and limited the liquid energy we get from 1-6 is.
NC: note that the GJ per acre for switchgrass is based on poor/marginal soil usage.

Stuart: I've asked David for a copy of his paper because this piecemeal GJ posting is confusing everyone.

For instance, here's an 04' Swedish study using wheat (having much less tonnage/acre than switchgrass) that asserts,

"The energy balance of the transportation fuel chains analysed varies from 1.3 up to 2.4, and the net energy output from about 20 up to about 60 GJ per hectare."

What this should tell us is that if we let our soil go too far, we are well and truly screwed.

Economists who think soil can be "mined" for value and discarded need to consider that food is an essential product and there won't be anywhere else to invest.

So let's see - all we need to do is to talk a bunch of farmers who are staring at $4 per bushel corn ($600/acre net @ 150 bushels/acre) into fallowing their land for at least one year, planting perennials that won't give much harvest for several years, with the ultimate prize of being able collect $30/ton @ 6 tons per acre ($180/acre net).  Oh, and we'll probably want them to sign a 10 year contract to keep their land in the perennial grass to make sure we have enough feedstock to justify putting the capital into a Fischer-Tropsch plant. Never mind that this will bankrupt any farmer if (make that when) land rents rise.

Repeat after me - this will never happen on enough of a scale to make a difference.  Good corn land in Iowa is currently going for around $5000/acre, which means rental costs of at least $250 an acre per year.  The numbers on biomass simply do not make sense except as a bit fuel.

For the "corn stalks as biofuel" crowd - I spent a fair bit of time over thanksgiving with an uncle who works for a major seed corn company, and he (and I) expressed shock at the number of farmers who are ALREADY removing the corn stalk detritus to use as cattle feed - they spread dried distiller's grain from ethanol plants on it and the cows munch it right up!  So much for that as a source of biomass.  I have come to the conclusion that corn ethanol will kill the possibility of any biomass conversion taking hold, at least in the midwest...

I thought the point was to grow grass in places where corn doesn't grow.
As a farmer (olives not corn), I can say that there are a lot of "scientists" that love to experiment with Gov. money.

Bio fuels are a myth as far as EROEI goes IMHO. We need to power down , conserve , and reduce births (die off occurs naturally)

jmy in Ca

You've mixed your units, compared apples to oranges, and done the math wrong. Other than that, thanks for your analysis.

  1. You cite $600/acre net for Iowa corn but that is really gross income, not net. For most farmers, net income is approximately $0/acre given recent corn prices until the most recent spike.

  2. The study was conducted on "agriculturally degraded and abandoned nitrogen-poor sandy soil". You then compared that to prime Iowa cropland at $5000/acre with yields of 150bu corn/acre. What do you think the yield in corn would be on this land? I bet it won't be 150bu, and it might be very close to zero bu/ac.

  3. The study quotes 68 GJ gross energy output/ha, with 28GJ net energy after conversion to synthetic diesel via FT. That comes to about $150/acre net income for agricultural wasteland compared to approximately $0/acre net for most farmland (prime Iowa cropland excluded).

  4. Conversion to electricity in a coal-fired powerplant, as quoted in the study, nets about $200/acre (assuming 10 cents/kwh). That's with low inputs, on wasteland, producing carbon-negative electricity.

I agree this will never happen ON GOOD IOWA CROPLAND. At least until the original 20 or 30 feet of loess is finally eroded away by corn cultivation (we are maybe 1/3rd of the way through the loess, IIRC).

My analysis above also confuses net and gross income, since there is mention of how much of the net energy income is available to the farmer as net dollar income. But compare that to current corn-to-ethanol production which produces essentially zero net energy, and precious little net dollar income for the farmer.

LOL - nice work happyfew... you've saved me some time with your excellent post.

I'll be responding in greater detail to this thread shortly.

You just compared apples to oranges too:

The study quotes 68 GJ gross energy output/ha, with 28GJ net energy after conversion to synthetic diesel via FT. That comes to about $150/acre net income for agricultural wasteland compared to approximately $0/acre net for most farmland (prime Iowa cropland excluded).

How did you come up that 150$ is the net income? Did you factor in the expenses to grow, harvest and transport the switchgrass to the F-T factory? Did you factor in the capital expenses for that factory and for all the machinery envolved? What Kyle did is comparing two gross incomes, but you compared gross to net icome.

After you substract all the expenses from the $150, then you need to compare the result to the income from alternative usage (as a pasture).

My guess is that after this, the whole enterprise will be an absolute nonstarter on large scale. There are certain reason why for example cellulosic residue from wheat is not used for paper production, let alone energy production. Namely these are the transportation and handling issues coming along with handling vast amounts of biomass. For a certain process to be economical, the inputs must be easier to obtain and deliver then the outputs.

You may not have read my last paragraph, where I admitted to the net/gross confusion, due to lack of data from the study. But if I had to read your post in Bulgarian, I would do far worse in the reading comprehension score.

I agree that biomass suffers greatly from a density handicap. We will never ship raw biomass from the Great Plains to coal powered power plants in the East, for example. But consider this agricultural data in context with Engineer Poet's plan to charify biomass as a source of FT feedstock and charcoal solid fuel. This process can happen on a local, small-scale, and the ouptuts can easily be shipped long distances in pipelines (charcoal by slurry).

The net income picture for the farmer is uncertain, to be sure, for this plan. But any crop that requires very low inputs has a big advantage over current practice. The net energy looks far better than corn-ethanol, and the externalized costs of current practice, if counted, would tip the balance even farther in favor Stuart's grassy Plains. If you add Engineer Poet's plan for carbon-sequestration credits, the farmer's income looks pretty stable.

Bottom line, though, show me a farmer making real crops, feeding a working gasifier, generating a large surplus in net energy, preferrably generating all his fuel inputs from his own production...

... then I will be excited. Until then, it is no more than an interesting idea that may be worthy of further study or even subsidy. We need a TOD biomass agricultural research station in Nebraska. We all chip in a few dollars a month to fund some basic research...

Or my plan...  cogen intergration of thermal conversion of gasified biomass to liquid alcohols as part of an continental Terra Preta regieme.
What's the field-to-wheels efficiency of your system, and the total production required to meet demand?
A brief response:

You cite $600/acre net for Iowa corn but that is really gross income, not net. For most farmers, net income is approximately $0/acre given recent corn prices until the most recent spike.

What planet do you live on?  Do you really think that there are all those farmers out there who were making no money at $2.50/bushel corn?  Have you ever been to "farm country" and seen the literal millions of dollars in equipment that are being used?  I realize that the 160 acre family farm can't make it at that price, but that's not the current reality.  And you basically prove my point - "until the recent spike."  With ethanol growing like it is, who can say that the "spike" in corn prices is any different than the "spike" in oil prices?  So you are netting $2/bushel instead of grossing $4/bushel - why would a farmer, as a businessman, switch from growing a cash crop like corn that has a proven market, subsidies in place, and the flexibility to adjust his crop every year to beans or whatever based upon market conditions?

The study was conducted on "agriculturally degraded and abandoned nitrogen-poor sandy soil". You then compared that to prime Iowa cropland at $5000/acre with yields of 150bu corn/acre. What do you think the yield in corn would be on this land? I bet it won't be 150bu, and it might be very close to zero bu/ac.

How much acreage is there of this type?  To get the kinds of biomass flux that are needed to support biomass ethanol or electric generation, DENSITY is vital, i.e., a lot of land needs to be planted close to the generation site.  Moreover, that land needs to be farmable - no 30 degree slopes, trees growing on it, etc.  

The study quotes 68 GJ gross energy output/ha, with 28GJ net energy after conversion to synthetic diesel via FT. That comes to about $150/acre net income for agricultural wasteland compared to approximately $0/acre net for most farmland (prime Iowa cropland excluded).

Using 10 GJ per ton, that ends up being about 3.5 tons biomass per acre.  So you're assuming $40/ton or so NET for the biomass, which is probably in the $70/ton GROSS cost to the producer, minimum.  From that ton, the producer gets somewhere in the neighborhood of 30 gallons FT diesel.  So we're close to $2.50/gallon for feedstock costs alone.  Capital, labor, and other costs are going to add another dollar to this.   This is not going to be cheap fuel.  The level of that cost suggests EROIs in the area of 2-3 to me.  

Conversion to electricity in a coal-fired powerplant, as quoted in the study, nets about $200/acre (assuming 10 cents/kwh). That's with low inputs, on wasteland, producing carbon-negative electricity.

Then why isn't it being done now?  The coal lobby?  Inertia?  Will these factors vanish?  

You may have confused my comments with a like for corn ethanol.  Let me set the matter straight:  I think corn ethanol is the stupidest method to generate biofuel.  However, I am not at all convinced that any of these solutions to biomass ethanol will work, and more importantly, will work on the time scales/cost scales that are needed.

Just for information, current farmgate value of switchgrass biomass in Tennessee is $70/ton - see

I'll reiterate:  Why isn't this being done now, if it is such an easy thing to do?  At $70/ton, there apparently is roughly $500/ha laying around that nobody wants, more or less cost free!  This means:

(1)  All farmers are stupid for not taking advantage of this, or

(2)  The production cost really is about $70/ton, meaning there is very little money to be made in doing this, or

(3)  It literally doesn't scale to levels that will meet current demands from livestock.

I don't buy (1), and (2) and (3) don't bode well for the future.

Hmmm. I think it's better to look at this a bit differently. This is a research paper exploring a new idea written by some scientists. Generally speaking, it is a long road for an idea to go from "research prototype" to "viable business". On the one hand, it's certainly right to explore whether this idea might or might not be able to travel that road. OTOH, it's not reasonable to expect it to be adopted instantaneously. Nor is it reasonable to dismiss it because it's not the entire answer all by itself.

To my mind, the correct question is whether this has any potential to be one of the numerous wedges required to solve our societal energy/climate problem. For that to be the case, there would need to be some land somewhere that can be more profitably utilized this way than that land's current most economic use. If that's not true today, then are their plausible conditions under which it would be true in the future? (Eg payments for carbon sequestration, improvements in cellulosic ethanol technology etc). That's a very different question than whether all cornland should be converted real soon (if it wasn't obvious, my prairie comment was tongue-in-cheek).

You've mixed units again. Farmers with millions of dollars worth of equipment and land also have millions of dollars of DEBT. Excepting, again, the prime Iowa corn farmer, the NET worth of many farmers is approximately zero. Their GROSS assets are quite large, but not their net. Once the suburbs reach their farms, their land appreciates astronomically and they cash out for a huge profit. Until then, they are operating at a negative net cash flow, sustained by ever larger bank loans.

"Then why isn't it being done now?"

You answered that in the first part of your post.

Subsidies. Farmers grow what is profitable and predictable - their bankers will demand it. If subsidies provide a stable, large part of gross farm income, they will grow what the subsidies demand, even to the point it is no longer profitable (but it's still predictable, so the banker is somewhat happy). If carbon sequestration and net energy farming were subsidized, maybe we would see farmers adopting something like Stuart's proposal. But let's not pretend that farming is a free market, where only the most efficient crops are grown, based on net dollars or net energy.

Calculating EROEI from the data given seems premature. It could be as low as 2-3, as you suggest. It could be as high as 28/4 (net of FT process/fossil fuel inputs) = 7, depending on what they really mean by "net" in the study.

"How much acreage is there of this type? "

Based on Stuart's graph, there are about 20 acres of marginal land for every acre of prime cropland. Much of the former prairies are flat, easy to mow, receive a modest amount of rainfall, have fertile soil, are not diluted by other types of unusable (for biomass) land. But I don't think I should have to point this out. You sound like someone familiar with Midwestern geography.

Have you talked to many farmers lately? They are not doing well. Food prices are bouncing off all-time lows, adjusted for inflation. Input prices are near all-time highs. They need some new ideas. Subsidies for more of the same seems counterproductive, to say the least.

I, too, agree that corn ethanol is stupid. I think cellulosic ethanol is nearly as bad, even if every optimistic projection comes true. I think depleting fossil fuels, fossil water, fossil deposits of phosphates, and the richest soils on the planet in the Great Plains to feed a political vote-buying scheme is really bad. Doing all that to feed an explosive growth of human population, unsustainably, seems the worst of all. Something about Bob and yeast comes to mind.

Those same farmers might take a second look at good prices for their straw and stover.
Stuart, first of all, from someone else who contributes to this website, to put up 3 stories with graphics in 3 days is prolific. I dont think people understand how much work some of this stuff his. I dont know how you do it.

Id also like to make a point about multiplier effects which isnt completely related to your post but is to any scheme to replace our fuel needs.  We use fuel to power modern society, which includes a long, complex chain of consumption.  If we replace our gasoline with biofuels, that means we are then able to drive everywhere and consume other stuff, which also needs to be produced and may not be easily made from biofuels.

Can we make plastics from ethanol? Or medicine?

Essentially if Im allotted 10 barrels of oil to use in a year, my decisions what to use it on will require many other people to use oil. I dont know what the multiplier is, but its high.

The answers to what we face lie in changing our demand structure, not changing supply, other than to change supply as a transitional strategy.

I think the is a relationship between ethyl alcohol and ethylene via dehydration and polymerisation to create polyethylene.

What is your definition of 1.4 B hectares ag land? = Total arable?

As your later post indicates,   this wedge might be increased if permanent pasture-say 1/3, given the constraints of   harvesting permanent pasture, were switched to LIHD, while the more fertile soils are devoted to switch grass, if economically feasible.  My thought is that a considerable portion of lower fertility and/or low ppt crop land may show greater returns with switch grass, and coupled with LIHD pasture land production, total carbon sequestration of the wedge might increase further.

Whatever the FAO includes in "arable". I was just very roughly trying to establish what 3 tonnes/ha/yr means compared to the size of the (8 gigaton) problem. Obviously, there's no way any large fraction of arable land would get converted to this use.

I would guess that a significant fraction of "permanent pasture" is already de facto "LIHD" and sequesters some carbon (and presumably is part of the overall approximately 3Gt and growing natural sink that offsets the 8Gt emissions we put out).

Switchgrass is one of the dominant species of the tallgrass prairie but will do us no good. According to Pimentel and Patzek  
However, converting switchgrass into ethanol results in a negative energy return. The negative
energy return is 50% or slightly higher than the negative energy return for corn ethanol production. The two major energy inputs for switchgrass conversion into ethanol were steam and electricity production.

Like other biofuels, switchgrass is an inefficient device to convert coal or natural-gas to liquid fuels. We would be better served going directly via using fischer tropsch etc.

Any biomass removal steals nutrients from the soil (converting it to dirt) that must be replaced at a price: in  energy and other resources. In the case of prarie grasses np&k must be replenished.

Oh but "according to Patzek and Pimentel..."

P&P are to biofuels as Exxon-Mobil funded climate science is to GW and despite the fact that 90% of the scientific community has countered their claims, Pstarr and others continue to pull these jokers out of a hat as rebuttal to biofuel production because it's all they've got.

On the contrary, P&P's paper "Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower," Natural Resources Research, Vol. 14, No. 1, March 2005 is the perhaps the only peer-reviewed energy-return study of its kind. I believe the others (shapouri were published in government or industry newsletters. Pimentel pioneered life-cycle methodology in the 1970's in his analysis of refuse recycling systems, applied it to agriculture, and then biofuels.

Are you sure 90% of the scientific community disagrees with P&P? It could be only the component funded by Archer Daniels Midland, Cargil and the other agriculture commodities dealers who want to sell ethanol that question his results.

It is pretty clear that all nothern temperate agricultures will not float the biofuel boat. I am in serious doubt as to the veracity of palm and sugar claims as the studies claiming positive eroei are not in peer-reviewed journals

Farrell et al.2006

Is but the most recent study of many peer reviewed papers on the subject that destroy Patzek and Pimental and yes, I am quite sure that 90% of the scientific community disagrees with them.

Corn and sugar ethanol are net energy positive without question - a fact that has been proven time and time again.

Your attempts to obfuscate the issue are quite sad.  

So once again you pull out the paper led by Farrell, the engineer who not so long ago was expending his energy promoting hydrogen cars, in another futile attempt to discredit Pimental.  Can you do no better?

Again, there is no future in liquid fuel from prairie grasses.  The future is food and solid fuel for heat, especially space heating.

I suggest you change your trade, though perhaps you are so accustomed to subsidies that you prefer to remain on the dole.  Well, there is always the chance the Pentagon can find you folks another make-work project.

I'm done.  You haven't done any better, since you provide no evidence that any liquid fuel process involving the use of temperate zone perennial grasses as feedstock comes remotely close to the efficiency achieved by using these feedstocks in the provision of densified solid fuel for space heating.  

The reality remains that the farmer will produce for the buyer who provides the greatest return per acre.  Without the public dole, the liquid fuel industry will never compete with the solid fuel industry.  It is strictly a function of the energy return from the two processes of converting sunshine into concentrated and marketable energy.

Money spent on the corn, etc, ethanol industry would be better spent providing poor people a paid ocean side holiday.

I heard Farrell speak at U.C.Berkeley and he admitted that 3 of the 6 papers he used in this study were not peer-reviewed. If the USDA-sponsored scientists published in peer-reviewed journals, they'd be laughed at.  The big deal with peer-reviewed papers is that you have to reveal your data to other scientists.  You can say whatever the hell you want otherwise.  Non-peer-reviewed papers are like fortune tellers and evangelical preachers telling people what they want to hear.  And just as religious leaders grow rich by telling people there's life after death, so do ADM and other corporations profit from the subsidies provided for ethanol.    If this were all a grand scheme to prevent coal from being burned in the future, I'd join the ethanol church myself.  But I'm pretty sure it's a sad and tragic get-rich-scheme for Wall Street types that will bankrupt our topsoils.
only three? Which of the above are original peer-reviewed studies?
It takes work to figure out which 6 citations are the papers used in Farrell's science article, the best way to figure it out is from a table in the supplemental material:

T. Patzek, Critical Reviews in Plant Sciences 23, 519 (2004, 2004).

D. Pimentel, T. Patzek, Natural Resources Research 14, 65 (March 2005, 2005)

M. E. Dias De Oliveira, B. E. Vaughan, E. J. J. Rykiel, Ethanol as Fuel: Energy, Carbon Dioxide Balances, and Ecological Footprint. BioScience 55, 593 (July, 2005).

H. Shapouri, J. A. Duffield, A. Mcaloon, paper presented at the Corn Utilization and Technology Conference, Indianapolis, June 7-9 2004.

M. Graboski, "Fossil Energy Use in the Manufacture of Corn Ethanol" (National  Corn Growers Association, 2002).

M. Wang, "Development and Use of GREET 1.6 Fuel-Cycle Model for Transportation  Fuels and Vehicle Technologies" Tech. Report No. ANL/ESD/TM-163 (Argonne  National  Laboratory, Center for Transportation Research, 2001).

Here are a few passages from the only positive net energy peer-reviewed paper (Dias De Oliverira et al):

United States: Major impacts

Pimentel and Pimentel (1996) point out that corn causes serious soil erosion  in the United States, amounting to values of approximately 22.2 Mg per ha, which is 18 times faster than the rate of soil formation. Pimentel (2003) also
reports that in some western irrigated corn acreage, groundwater is being mined at a rate 25% faster than the natural recharge of its aquifer. According to Donahue and colleagues (1990), as cited by Pimentel (1997), 1 ha of corn
transpires approximately 4 million liters of water during its growing season, and an additional 2 million liters per ha evaporates concurrently from the soil.

Loss of biodiversity

With large extensions of monoculture, native habitat loses space to agriculture. As a consequence, fauna and flora are lost, thereby reducing biological diversity. Odum, cited by Wackernagel and Rees (1995), suggests that one-third of every ecosystem type should be preserved to secure biodiversity. Moreover, large-scale production of energy crops will undoubtedly result in an expansion of energy crop monocultures, which could ultimately reduce yields because of increased pest problems, diseases, and soil degradation (Giampietro et al. 1997).

Ecological footprint: Comparison of benefits and disadvantages  

For the US production of ethanol, even without considering the environmental impacts, the results show that this option is not a realistic alternative. The major constraint is the amount of land area required for corn plantations. Running the STELLA model using current ethanol production conditions, and assuming an annual increase of 4% in the US automobile fleet, we determined that by the year 2012, all the available cropland area of the United States would be required for corn production. This scenario assumed that the whole automobile fleet would use E85 as fuel. In the same scenario, by the year 2036, not only the entire US crop-land area but also the entire land area now used for range and pasture would be required. Finally, by 2048, virtually the whole country, with the exception of cities, would be covered by corn plantations.


The use of ethanol as a substitute for gasoline proved to be neither a sustainable nor an environmentally friendly option, considering ecological footprint values, and both net energy and CO2 offset considerations seemed relatively unimportant compared to the ecological footprint. As revealed by the ecological footprint approach, the direct and indirect environmental impacts of growing, harvesting, and converting biomass to ethanol far exceed any value in developing this alternative energy resource on a large scale.

In the US case, the use of ethanol would require enormous areas of corn agriculture, and the accompanying environmental impacts outweigh its benefits.

Ethanol cannot alleviate the United States' dependence on petroleum.

Are you paid to be here?  I've often wondered this, but to my knowledge no one's ever asked you before.
It could be only the component funded by Archer Daniels Midland, Cargil and the other agriculture commodities dealers who want to sell ethanol that question his results.

You mean like the way Exxon/Mobil funds "research" that questions Global Warming?
I geuss you didn't read the whole article. Patzek and Pimentel must have assumed the use of large amounts of fertilizer and irrigation on the scale of dry land corn farmers. What the article describes is a decade long experiment where irrigation is used for a short period in the first year and none in subsequent years. Native grasses have evolved to take nitrogen and other nutrients from root fungus and bacteria. Therefore fossil fuel input for fertiliser is absolutely zero.
Patzek and Pimentel are spokensmen for those who want farmers to keep buying fossil fuels and their byproducts.
Maybe switchgrass can't replace more than a few percent of liquid fuel use but it would be more than enough to keep our agricultural systems working.  
I have studied the report and the critiques and claims for irrigation and fertilizer over-dependence do not swing the energy equation to the positive.

Your claims for zero fossil fuel fertilizer is nonsence. Native grasses are just that grasses and do not fix nitrogen on their roots like legumes. Any such crops require appications of NPK fertilizer when plant material is removed from the soil, as is the case with agriculture.

Once again, claims of conspiracy and corruption are unfounded and only distract from the debate. Pimentel is on the faculty of Cornel, a reputable scientist, and a long-ime proponent of sustainable agriculture. Regardless, organic agriculture system would be no better as primary fuel producers as they to are heavily dependent on off-farm nutrient input which requires energy.

Our fossil-fuel-dependent agriculture system will continue as long as there is petroleum in the ground. The question is: will be on a scale that feeds the world's growing populations or will biofuel diversion to power our overconsumptive lifestyle make that impossible?

"BIOHEAT offers the best energy and greenhouse gas balances of the available options and is the most efficient way to produce energy from farmland," says David Pimentel...

At this same url, readers can find notice of:

Thursday January 25th, 2007
1:00-5:00pm, Guelph University Centre, Guelph ON

An introduction for farmers, energy consumers, researchers and bio-energy project developers on the emerging "BioHeat" Industry

Pimental's views on bio-heat are shared by another Cornell scientist:

Liquid fuel from farmland is wasteful folly.  Solid fuel, using easily densified grasses such as switchgrass, can be produced from marginal farmland with a sufficiently high energy return to justify the activity.

A little further down the natural gas production decline and the debate will be over.  Resistance is futile.

Pelletized grass. Appropriate where there is no wood (like furnance corn fuel) but requires extra processing (with some loss of efficiency) for compression and shaping.

But why choose a pelletized forced-air heater when a well-constructed mason stove is more efficient, comfortable, convenient and doesn't require electricity.

Time to toss in my standard comments (repeat 'em often enough and maybe somebody will listen sometime soon- or not soon)

  1. Biomass is great for space heating, use it to replace all the liquids and gases now used for that purpose, and put thouse L's and G's into transportation.

  2. And while you're at it, use the same biomass for cogen, making both heat and electricity for bldgs ( free piston stirling engines, of course). This saves a lot of coal. Engineer-Poet is very good at calculating this kind of stuff and might be willing to tell you just how much. EP will rightly say that carbon fuel cells would be better, but when do we get 'em???

  3. And as for farm power, solid biomass again.  Why bother with diesel or ethanol when those same stirling engines would do just great?  Don't have any?  Well, there's lots of unemployed engine engineers just looking for something to do, ahd this is something to do that's worth doing- and not even that hard.

  4.  Now all we have to do is think of a way to cut the population down to maybe 30% of what it is now and we have a paradise. And I am NOT  thinking of machine guns.
Don't burn grass in stoves, burn gasified grass in high-temperature fuel cells (60-80% efficiency with bottoming cycles).  When you need heat, use heat pumps.  This gives you:
  • Space heat (up to 2.5 units per unit of bio-energy input).
  • Electricity.

Burning biomass in stoves only gives you space heat, and a lot less for the same input.  Neither does it let you seamlessly trade off other sources such as wind power to reduce bio-fuel consumption, allow you to replace motor fuel (via PHEV's), or any of the other advantages of fungible energy supplies.

The more I read, the more I get depressed.

I think everybody here is enjoying a nice delusion.

Unfortunately, once you start going to solid pellets (which I agree is probably best) you are in the coal arena.  And despite its horrible climate effects I have the feeling that overwhelmingly it will go to coal, because of the much larger energy gain and ease.   Do you think there will be carbon taxes?   I think that's very unlikely.

I think the only realistic modestly feasible path is nukes and plug-in hybrids whereby we can squeak through

Look at the state of the science: people are still debating whether the fundamental thermodynamics might work.   Message to me is that if it does work, it is marginal.  And people are assuming multiple technological miracles.

Better batteries---and by this the primary limiting factor is now long-term degradiation---are the only technological miracle needed for PHEVs and are likely to come much sooner than deployed cellulosic ethanol or large scale pelletized, gasified whatever.

Unfortunately I see the most likely situation going to PHEVs and titanic climate destroying coal deployment in all forms.

Unfortunately I have to agree; the world is going to fatally OD on coal. Despite  Al Gore and forums like TOD we seem unable able to slow the relentless rise of coal. I think this guy is basically correct Dwindling hydro is being supplanted by coal in Brazil, China and my home state of Tasmania. TOD posters inform us even Germany is going the coal route despite massive investment in wind, solar and biofuels. We've grown too lazy to make the effort in difficult biomass energy so long as coal is dirt cheap. If enough people survive peak everything including peak coal circa 2040 maybe there will be a chance to make a fresh start.
It is at least theoretically possible to burn coal without dumping CO2 in the atmosphere.

Should that become the standard practice, the climate will be safe until coal eventually runs out.  At that point the risk is over.

I think we'd be in much better shape switching to renewables now, even if technology would be better then.

The more I read, the more I get depressed.

There's always Soylant Green :-)
Back in the mid 1900s soldiers on horseback got lost in the 12 foot high native grasses of Iowa.  Who was adding nitrogen back then? The nitrogen came from wildlife, worms, insects, fungus, and bacteria. The abundance of thunderstorms also fixed nitrogen via lightining's effect.
But those prairies were left to grow for millenia. No one needed to add nitrogen, phosphorous, or potassium because these critical nutrients (and others) were allowed to recycle back to the soil when a plant died.

Biofuel schemes remove all the mass, including these macronutrients, the carbon, and many many micronutrients and animal matter necessary for 'dirt' to be 'soil.'

Thunderstorm and man-made nitrogen pollution do add a bit of fertilizer but not in amounts necessary to sustain an ecosystem if that ecosystem is plundered.

Management, or just 'nudging' the soil food web in the direction you want would be helpful in increasing yields or carbon sequestration.

(Ms. Inghram has a clame to fame - she put the stop to one of the early 'lets make biomass into booze' schemes.)