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New Studies Identify Change in Land Use Associated with Biofuel Production as Major Contributor of Greenhouse Gases, Far Offsetting Benefits of Most Current Biofuels

Two separate studies published in the current online edition of the journal Science identify land use change—the conversion of rainforests, peatlands, savannas, or grasslands to produce food-based biofuels or to replace existing cropland diverted to biofuel crop production—as a major source of increased carbon dioxide emissions, far offsetting the presumed greenhouse gas benefits of using most current biofuels.

The studies stress the importance of using biomass waste or biomass grown on non-agricultural lands as feedstock for biofuel production to avoid this problem.

Timothy Searchinger from Princeton and colleagues at Woods Hole Research Center and Iowa State University used a worldwide agricultural model to estimate emissions produced by the change in land use as farmers worldwide respond to higher prices and convert forest and grassland to new cropland. They concluded that corn-based ethanol, instead of producing a net 20% savings in greenhouse gases, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on US corn lands, increase emissions by 50%.

In their study, Joseph Fargione from the Nature Conservancy and colleagues at the University of Minnesota, calculated that land use conversion in Brazil, Southeast Asia, and the United States creates a ‘biofuel carbon debt’ by releasing 17 to 420 times more CO2 than the annual greenhouse gas (GHG) reductions these biofuels provide by displacing fossil fuels. In contrast, they said, biofuels made from waste biomass or from biomass grown on abandoned agricultural lands planted with perennials incur little or no carbon debt and offer immediate and sustained GHG advantages.

In the worst case Fargione and his colleagues examined, converting peatlands in Indonesia into palm oil plantations ran up a carbon debt that would take 423 years to pay off. The next worst was soybeans in the Amazon, at 319 years.

Searchinger et. al. note in their paper that “land use change emissions” refers to all of the carbon storage and ongoing sequestration that is foregone by devoting land to the production of biofuels. Using land to produce a biofuel feedstock forgoes some of that storage and ongoing sequestration, causing offsetting emissions in a variety of ways.

  • A forest or grassland can be directly converted to grow a biofuel such as corn, resulting in the direct loss of the carbon in the standing trees and grasses and a fair chunk of the carbon after plowing up the soils. Soils store major quantities of carbon in forests and grasslands.

  • The same land, if not devoted to biofuels, could continue to sequester carbon. For example, a young, growing forest will continue to sequester carbon as the forest grows for many years. This ongoing sequestration is lost if the land is converted to a biofuel for ethanol. (Although land converted to grow the biofuel, such as corn, will continue to sequester carbon, the typical biofuel analysis already takes account of that carbon.)

  • Both of these effects can occur indirectly. For example, if corn in the United States is diverted to ethanol production, grasslands or forest could be converted anywhere in the world to replace the corn. Complicating this analysis, these indirect effects can pass through many steps. For example, soybean land in the US can be planted in corn, and forest or grassland plowed up in Brazil to replace the soybeans.

In essence, under typical biofuel calculations, the carbon withdrawn from the atmosphere by growing the feedstock becomes a greenhouse gas credit. We call this credit a feedstock uptake credit, which we treat as part of the overall land use effect. But the world’s land already exists, and that land is for the most part removing carbon from the atmosphere each year and in most cases has stored substantial amounts of carbon for decades that may be lost if used to produce biofuels.

The proper focus must be on the net change in carbon removed from the atmosphere that is either stored by land or used to replace fossil fuels. (Replacing fossil fuels is a form of storage because the unneeded fossil fuel remains stored underground.) An accurate accounting must subtract the emissions from land use change from the feedstock uptake credit to produce a proper net estimate of the overall land use effect—the effect of using land to produce biofuels.



Mark Delucchi

These are responses to “Grey Falcon”

Alex Farrell has jumped into this relatively recently. His participation has no bearing on the facts of the history of the research. DOE (apart from the national labs) doesn’t do much in this area, and USDA is more interested in promoting biofuel development than in comprehensive analysis.

I don’t understand the relevance of Dr. Crutzen’s findings in this regard.

I don’t understand the relevance of Sperling’s and Farrell’s frustration.

Increases in N emissions can in fact cause cooling, via nitrate aerosol formation, N deposition and fertilization in N-limited ecosystems, reduction in the lifetime of CH4 and reduction in formation of sulfate aerosol. Changes in albedo can in fact cause cooling.

The reversion of land uses can, in principle, completely cancel the original effects, even including any “compounding,” because the reversion can give rise to, in effect, negative compounding. There is much more to say about this, however; much more than can be discussed here. If you are interested I suggest you contact me offline.

I agree that the findings regarding land-use change should give us pause; I’ve thought this for almost 20 years.

Scott S.

It would be interesting to see how the equation changes for fuels made from waste material rather than from land propositioned solely for biofuels as described here:


It depends on what is meant by "waste". I do not think that we are going to power all of our cars from suburban grass clippings. There is a lot of paper and card board waste that could be used, but much of that can be recycled as well.

When I think of waste, I refer to farm and forest biomass that can not be used for anything else. If you throw it in a landfill, it will decay and produce CO2 and methane. While I think tapping landfills for methane is better than letting it get into the atmosphere, it is after the fact.

Take the farm and forest "waste" (stover, stalks, straw, limbs bark, etc.) and make methane to heat our homes and fuels to run our cars. That way, it does not end up in land fills in the first place. But this will take coordinated effort, which takes leadership. That is something that we have been in short supply of lately.


As noted above, biofuels is reason #54 for deforestation. The major causes of deforestation are population pressures, poor property rights (legal systems that allow the privatization of public lands or expropriation of private lands), and the general low monetized value of forests to private individuals.

Any new commercially viable product that takes substantial amounts of land to produce (and doesn't substitute for another product dependent upon land to produce) will add to deforestation. It doesn't really matter which land the new product is grown upon. It will displace crops in one place that have to find new land to grow upon.

This displacement process will also tend to increase the costs of all other crops. Therefore, it doesn't really matter if the new product uses switchgrass, rice, or corn as a feedstock. If any of the land currently used to produce those feedstocks is converted to the new product, supply of the old output corn, wheat, rice will go down. If supply goes down and demand doesn't change, the price goes up.

The price of all products that depend upon substantial amounts of land as an input will increase because land itself has become more valuable due to the new use. That cost will be passed on to consumers.

Industrial agricultural production has many substantial environmental impacts. Water usage and pollution are the two biggest that come to mind.

If it is worthwhile to address the land use issues involved in biofuels usage, focusing only on the land the actual fuel is grown on (as the new EU rules do) is meaningless. If the concern is land use changes, the policy should look at overall land use patterns in the originating countries. Doing so will give many more people a stake in preserving the forests. It will effectively monetize preservation of the forests.

Similarly, if the concerns are the industrial production practices, overall agricultural impacts should be looked at. In short, any plans for intensive crop production of biofuels should be removed sooner rather than later.

Biofuels production is helping to raise income levels in the agricultural communities around the globe. Two groups would be naturally opposed to biofuels. One is the petroleum industry which stands to lose pricing power greatly limiting income. The other are the radical environmentalists who object to anything that increases instead of decreases the amount of human agriculture.


==Take the farm and forest "waste" (stover, stalks, straw, limbs bark, etc.) and make methane to heat our homes and fuels to run our cars. That way, it does not end up in land fills in the first place.==

Excuse me.
But thats not waste either.

Raw sewage, and material going into a landfill that truly can't be recycled.

Thats "True Waste".
But there is hardly any of that to go around.

Certainly not enough on a scale more meaningful than the 3% mileage benefit you gain merely by inflating your tires better.


The ethanol plant in Georgia seemed to think that there is enough left over forest material to make fuel. I do not think that they would have gotten the grant nor investors if there was not.

You either make products out of it, burn it or do something else with it. If it is more profitable to make ethanol than to burn it to produce heat and or electricity for the process, then that is what they will do with it.

If there is a shortage of plywood or particle board because of this, that will be the trade off. If there is less animal fodder or feed if the straw and stover are used for fuel, then that is the trade off. Sometimes options in life ARE trade offs and we have to decide how we balance them.


The main reason those aren't considered "Waste" is that:

1. Stover, and farm "waste" is usually used to regenerate the soil. And we're already losing topsoil at an alarming rate. Take that out, and you're create a barren wasteland. If you take minerals/organic compounds out of the soil, and you don't put them back, they don't magically reappear the next time you plant something. And all we put back as fertilizer is Nitrogen Potassium and Phosporous. (NPK) That doesn't cover the whole swath of whats needed.

2. As for the Trees thing, a german study was pointed out that forrests which contain dead trees maintain a lot more carbon than cleared forrests.


Now it's certainly technically possible to take that stuff out and incinerate it.

But I wouldn't really call that "sustainable", or "green".


Especially since that particular "Ethanol plant in Georgia" (i.e. Range Fuels) is using the exact same infrastructure as a Coal-to-Liquids facility. (i.e. Fischer Tropsch) (Spelled with two "sch"s)


The consensus from some basic research on the matter a while back seemed to be that 1/2 of the stalk and straw biomass could be used and the other half should go back to the soil.

"It is estimated that 323 million tons of cellulose containing raw materials that could be used to create ethanol are thrown away each year."


I do not claim to be an expert on this and that is not the only source of information on the matter. I do think that it is good to get the facts out there to make better conclusions and decisions.

With all the talk on cellulose ethanol, the more true, real and factual information that we have on the subject the better off we all are. There has been so much spin and misinformation lately that some people may not believe anyone anymore on just about anything.


A question that came to my mind recently and for which I have no answer : if you look at the paper industry which basic material is "cellulose", they always used wood as livestock right ? a lot of forests are planted just for the paper industry (in finland for example) paper industry have decades of experience in cellulose production, right. So my question is : when it comes to biofuel, why perennial grass or corn stalk would be better at proving cellulose than forest an wood ? forest don't create soil erosion and protect lands ...


That may be why that one cellulose ethanol plant is locating in Georgia. A lot of that Georgia pine cellulose may go into fuel production. There may be some waste from pulp and paper mills that could be used as well. What was once considered a waste byproduct and something that was a headache to get rid of may become a new revenue stream for the companies and new a new fuel source for motorists.


As for the paper process, I suggest you read this:

In short, the paper making process is very energy intensive, as it physical rips the wood to shreds.


Georgia incidentally is going through a massive crippling drought right now.

They are getting so desperate, that they just introduced a bill to redraw their state line to take over a big river in Tennessee.

Last I checked, Biofuels are rather water intensive.


The Coskata process is suppose to use 1 gallon of water per gallon of fuel. If you gasify with catalysts, it might even be less.

"Coskata’s process uses less than a gallon of water to make a gallon of ethanol compared to three gallons or more for other processes."



It is clear to me that the cellulosic approach is way overvalued right now given that we have no evidence that it will work any time soon if ever. The Fisher Tropsh approach at least is proven but is not easy to run. Even is they find an effective way to turn cellulose in Ethanol there is still the problem of carrying 1 billion tons of biomass from field to biorefinerie plans. In my mind this can only be solved with small scale refineries that could be implemented at big farm level then minimizing the transportation distance from field to refinerie. I don't think a Fisher Tropsh plan can fit into that scheme.


They have made gasifiers and FT plants that will fit in a rural agricultural setting. Gridley, California did a pilot program years ago to prove that this could be done.

I see no reason why you could not have 100s of plants all across the Great Plains states right where the farming is done. You transport the methane by pipe and the ethanol by rail.

This would eliminate transporting the biomass more than 20 miles and you only transport the finished product. In the case of Substitute Natural Gas, you just put it in the NG pipe network.

This could be a real boost to farmers who sometimes get hit with low crop prices because all farmers come to the market with the same product at about the same time. We might be able to reduce farm subsidies and price supports which would free up funds for more renewable development.


Lots of sensible comments here, reasonably discussion around this topic promotes a greater understanding of the issues.
From doing nothing to all to commercialisation of the free market priority money making options, to tapping into the "waste" stream.
In an age when "WASTE" doesn't necessarily mean useless, or without value.
I like the idea that an unutilized byproduct "RESOURCE" stream can be constructively turned to value add.
Some forestry practices and 'Management' options may best be achieved through trash harvesting versus burning for fire hazard reduction, Urban green waste is a rich source of material for a number of end uses, some agricultural "wastes" can be at the same time with different handling techniques be either polluting, utilized, with secondary or tertiary value adding, or have a multiple number of options depending on the economics and product requirements.
Unquestionably there will be no one size fits all.
Studies such as this help by showing or challenging one size fits all or our own ideas.
Ultimately all projects are micromanaged at the coalface and better informed operators will have to make decisions.
These studies will help in that process, but cannot prevent human errors.


all food crops should be left on the table, other than oil in the fryer
that can be recycled as biofuel. Your forgetting one big peace of the
puzzle, see www.valence.net, algae. According to Valence Technologies,
using their vertigro system they can make 33,000 gallons of biodiesel
per acre and turn excess residue into ethanol. This can be done on non
productive land using sunlight, a little water, and carbon. The algae
can replicate itself 7 times per day. Also, www.solazyme.com, claims
that you can grow algae without sunshine by adding sugar to the algae,
increasing its yield beyond what sunshine can provide, and grow algae
at night. Algae farms can be sited next to any industry that is
producing carbon and recycle that carbon into algae, whose biofuel can
then be used in generators to totally electricfy the world and, recycle
the carbon generated back into the algae and, on and on, using existing
electric transmission lines. No emmisions! No greenhouse gases! No
wars! Electric vehicles! Clean, clean air!!! What are we waiting for?!!!


There's a podcast that can be heard for free on Science's website for those who are interested. It's very brief - the portion that includes the author of the land use study - but he admits that there are factors that they didn't consider and that the study is limited.

Someone mentioned earlier, too, the level of misinformation that is out there on the biofuel issue. This seems almost intentional. Discussions like the one on this blog are essential to raising awareness in a meaningful way.

I agree we need well-rounded land use policy/decision-making.

George Marchetti

In response to Jer's original February 8th comment, there are currently 36 million acres of land in the US soil conservation program. Perennial grasses (not crops) are typically grown on this land to stabilize the soil. This could be one source of woody (e.g., switchgrass or poplar) biomass for methanol, dimethyl ether or other second generation biofuels from non-crop agricultural land. Mapping is important and should be possible since the federal government funds the program.


"The studies stress the importance of using biomass waste or biomass grown on non-agricultural lands as feedstock for biofuel production to avoid this problem."

That pretty much sums it up. It is how we do this and not so much if we do it. Some people like to just say it can not or should not be done as a way of getting more information.

It also seems to be a trend to say that we can not get all of our fuels from this or if we did it would be a disaster. That is a way of defining boundaries and limits, but does not address the issue.

The issue is that we will need everything that we can think of to head off a major disruption to modern society. A little of this and bit of that will sum together and go a long way. Everything in moderation.

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