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Biofuels: not quite dead yet, thankfully

Nathanael Greene

Posted February 8, 2008

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So the questions I've been getting today are do yesterday's Science articles mean that all biofuels are bad and that the recently passed RFS is going to harm the climate? The short answer is no and no. It remains relatively easy to construct theoretical scenarios where biofuels contribute significantly to our transportation energy needs in a low-carbon way, avoiding the direct and indirect land-use traps addressed in the articles. The challenge remains how do we drive the biofuels industry to produce these types of biofuels.

Unfortunately, most stories today on the articles are righting off all biofuels and giving short shrift to the policy questions. (See this Wired story and this NY Times article.)On the other extreme, Bob Dineen from the Renewable Fuels Association calls these studies "simplistic," and in a comment on my post from yesterday, Tim Raphael from Pacific Ethanol tried to discredit the whole idea of indirect impacts.

The dynamics the authors have identified are undeniable--if you clear land to grow crop for biofuels you have to account for the emissions from that clearing and if you induce clearing by driving up crop and land prices, you also have to take responsibility for those emissions. For laying out these dynamics and giving us a sense of the scale, we all owe them a debt of gratitude, particularly Searchinger and his team because the emissions from indirect land are hard for many to understand. The analysis of the indirect land-use impacts uses one of the most respected agricultural economic models, but it is only that--one model. Others have been doing similar analysis using at least partly a different model and getting different results. And many folks will make the case for different assumptions and inputs into the models.

Fortunately, we knew about these dynamic before yesterday, and we’ve won a preemptive victory in getting the dynamics written into the legislation in the form of the land-use safeguards and minimum lifecycle GHG standards (which as I noted a few weeks ago include, by law, the indirect land-use emissions). Now we have to defend these provisions and make sure a scientific debate (not one issue of Science) guides the implementation.

So I would caution folks from assuming that either article means that no crop-based biofuels will be able to comply with the RFS or that their analyses are definitive. Of course, it is definitely possible (and taking Searchinger's numbers at face value very likely) that the amount of truly low-carbon biofuels we can drive through real politics and real markets is much smaller than we would hope. This makes the urgency around getting a federal low-carbon fuel standard all the greater. (See Roland's post on this too.) This approach broadens the competition among low-carbon energy supplies for transportation and focuses purely on the benefits we need rather than number of gallons produced.

The challenges of getting biofuels right also means that we need to step up our efforts on renewable electricity, transmission, and electrification of transportation. Similarly, demand reductions are almost always the cheapest, cleanest, and fastest way to reduce GHG emissions. We need to be looking for ways to dramatically increase VMT reductions and further increase vehicle efficiency (beyond our recent victory increasing CAFE standards).


But recall that we’re struggling with how to get biofuels on the right path not out of some perverse desire to work on difficult tasks, but because the other parts of the transportation solution set also face major challenges in scaling up and doing it quickly. The pie-charts above are based on very aggressive scenarios for plug-in hybrids and smart growth/VMT reductions and different levels of efficiency. There are no easy solutions to a low-carbon transportation sector that do not require a significant contribution from biofuels. The challenges facing vehicle efficiency, electrification, VMT reductions, smart growth are different from those facing biofuels (they lessen the benefits we can get instead of risking costs), but for me, they do mean that the just-say-no approach to biofuels is irresponsible.

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Brooke ColemanFeb 9 2008 06:31 PM

What is disturbing about these studies, and the analysis of them (especially in the press) is the total lack of sobriety about the issue, and what these studies actually say.

These studies basically say that if we plant a bunch of biofuels crops in pristine ecosystems, there will be a major climate hit. That is not a surprise, and as you point out, that is not one of the smart ways to produce biofuels.

Yet the press has gone hog wild and are writing off biofuels. Why? Well, partly because the press are easily fooled and over worked. But it's also because some of the authors of the report are making irresponsible statements. If Tim Searchinger thinks his analysis writes off CURRENT biofuels, he is mistaken. Perhaps you can help me with a few things ...

1) Searchinger puts 30 bgy of corn ethanol into his model. We are currently at 8 bgy, and federal law calls for 15 bgy. Why is no one talking about this?

2) Searchinger (and many other LCA researchers) seem to be overly at peace about seeking out 6 degrees of separation for biofuels (i.e. going way upstream to indirect impacts) and not doing the same for oil. Imagine if you came to a fork in a river, and you wanted to know which fork was putting more water in the river. So you hiked up the biofuels fork 6 miles, came back, and then hiked up the petroleum fork 1 mile, and came back. Someone says, "which fork puts more water in the river." You say, "biofuels fork." Guy says, "how do you know?" You say, "cuz I saw more water in the biofuels fork." Of course you did, you went farther upstream for biofuels than oil. In my opinion, it is simply absurd to strip search biofuels and let oil through using the old method.

You praise Searchinger. Maybe his intentions are in the right place. But in my opinion, he is letting everyone misunderstand what his analysis actually says because that's his agenda -- he is anti-biofuels.

Well, I hope people eventually see through the headlines. They won't if there is not a more intelligent discussion of his report.

Nathanael GreeneFeb 11 2008 12:35 PM

Brooke, Thanks for your comment. I agree that the press is jumping to conclusions but also think it would be irresponsible to ignore the laws of supply and demand. They're not physics and chemistry (which drive the direct emissions), but pretty predictable.

You raise an interesting point about making sure that we're using the same system boundaries with oil as we are with biofuels. I've heard some argue that we should be assuming that gasoline lifecycle GHG emissions will go up as easy sources of oil become scarcer. Keeping these emissions marginally lower is a benefit for which biofuels should take credit. Are there other dynamics related to oil that you think are being ignored?

Searchinger isn't anti-biofuels, he's anti-land clearing, as we all should be. You right that his baseline model is of a 15 billion gallon increase over 15 billion gallon base, and that's a problem. Elasticities are point values and shocking the system with such large changes undermines their predictive value. He does look at an increase of just half this size, and gets emissions just 10% less per acre of US corn devoted to ethanol. He could argue that the 30 billion gallon total in his model is still less than the 36 billion gallons just signed into law, but of course the majority of that cannot be corn ethanol. He's analysis of cellulosic ethanol make from crops grown on corn land is definitely a weak spot, but again the laws of supply and demand are going to apply, it's just a question getting better inputs.

Bottom line, there are lots of inputs and specific assumptions in Searchinger's modeling that need to be reviewed, but ad hominem attacks do not make a good counter argument. We need acknowledge the dynamic and figure out if his numbers are right and suggest alternative numbers and methodologies where we think they're needed. Saving the world from global warming demands nothing less.

Burl HaigwoodFeb 11 2008 03:03 PM

You present a very fair and balanced viewpoint and some valid concerns about our biofuels future, especially since you agree there should be biofuels in our future. However, I am leaning more towards Brooke Coleman and the need to assign more concern to oil. These new studies also leave a bad after taste that is hauntingly familiar to many anti-ethanol studies in the past. It appears that every time a study of this nature becomes public everyone is quick to forget why we are researching and developing alternatives to oil and new sustainable biofuel technologies. And there also always seems to be a missing argument against oil use.

Some how greenhouse gases and credit trading programs do not calculate very well when compared to emissions of war in the Middle east and the death of our soldiers, the constant threat of world terrorism fueled by oil, Iran’s nuclear program, peak world oil and lack of oil alternatives, record oil profits and growing world gasoline demand, and the increasing rates of poverty and starving children without health care (in the United States too) – much stemming from high oil prices. These moral issues always seem to be left out of the argument and therefore “deemed” not as valuable in comparison.

The United States is on the brink of some tremendous science and technologic breakthroughs that would not come to fruition without the new renewable fuel standard in the Energy Independence and Security Act of 2007. We are all on the brink of disaster if we do not something quickly to get new biofuel technologies out of the research box and into the market place to fully develop. If we don’t do it soon it is very likely there won’t be anyone left in a financial community to spur biofuels development, or consumers who can afford to buy them. The recent studies appearing Science are just creating some more alarmist fodder about biofuels that may lead to some serious and perhaps intended consequences – no more research and development into new biofuels.

Thank you for keeping the biofuels conversation in the middle of the road. It is way too early in the game to be looking at the off ramps.

Brooke ColemanFeb 11 2008 05:33 PM

Thanks for the response Nathaniel.

The problem with not looking at the oil baseline is more general than what you mention. A comparison of biofuels with indirect impacts to an oil baseline without them has very limited value. We could list the indirect impacts of oil all day long, but know this, Searchinger did not apply ANY land use changes to the oil side (whether they are big or small). You have The Nature Conservancy and other supposedly green groups saying "these fuels are worse than oil on GHG" and they don't even bother to make it an apples to apples comparison? There is an entire industry dedicated to harvesting lumber in conjunction with oil drilling, and that's just one example. There is no infrastructural element to GREET. How much oil do we burn every year on non-offensive resource protection of Straits, pipelines, etc.? The list is endless.

I understand your supply and demand comment, but Searchinger's assumption that a hectare of land used for ethanol in the U.S. will automatically be replaced by a hectare in a rainforest is not particularly productive UNLESS he is careful to note that his analysis is a worst case scenario analysis, which he definitely did not do with reporters or anyone. I find this unprofessional, frankly. There are too many things at work here to do that, including tariffs, yield increases (his yield assumptions are not realistic BTW), socioeconomics, etc. I confess that IF he had been responsible, and said to everyone "this is how bad it could be", then his analysis is useful (although it still has the oil baseline problem). But he didn't, and he should be criticized for this (people assume "Science" is objective).

Finally, you mention that he looked at an increase of half this size. So he looked at about 23 bgy of corn ethanol (still way over the 15 bgy/2016-2022 federal policy). But this does not make me feel any better because models always have hot spots, which basically means thresholds where the response gets much worse very quickly, then only marginally worse thereafter. Where's the hot spot in this model? Is it public? I find it dubious that 8 bgy and 15 bgy were not run. Those are the most relevant numbers to run.

These are useful questions to ask, but the authors have gone over the line of being credible in their apparent thirst for a media splash. That is my opinion ... but when you look at what the actual studies say, and the assumptions that are made ... I think it's a supported opinion.

David BlumeFeb 12 2008 02:04 PM

First ofall you can't legitimately compare ethanol production to petroleum production when it comes to GHG. As I point out in my book Alcohol Can Be A Gas, oil is dwindling fast and the true comparison is to oil shale, tar sands, coal to liquids and methane clathrates. That's where MegaOilron is going if we don't develop biofuels and most specifically alcohol. Those other sources are as much as hundreds of times the impact of petroleum on air quality and climate change. Plus these studies as well as others are at odds with the Dec 6, 2006 Science study which is the only study to look at polycultures of energy crops and the full carbon absorption including that which is exuded from the roots which accounts for up to 80% of the carbon absorbed by plants. These other studies ignore these contributions so their numbers are nothing more than an academic exercise but have no relevance to the real world The 12/6/06 study shows that 13+ times the CO2 is absorbed than is produced in the farming and burning of alcohol. For more information see

Jim BullisFeb 12 2008 02:51 PM

Ethanol is fundamentally a sustainable fuel, since every hydrocarbon molecule that is burned was derived from carbon dioxide at some relatively recent time.

But the rate at which we now use fuel is far beyond the capacity of our cropland or forest land, if well managed. There seems to be a clear danger that the use of ethanol will overwhelm both agriculture and forest management.

If there is a clear path toward reduced demand, then, and only then, should we get enthusiastic about ethanol.

There are things we could do to greatly reduce use of energy and still sustain our present life style. Rethinking of the way we ride in cars and the way we produce electricity is necessary, but given such readjustment, there are promising possibilities.

The website, shows some examples. (No products or services are offered at this website, though I have an interest in Miastrada.)

Rebecca RockefellerFeb 12 2008 08:28 PM

Searchinger makes a valuable contribution to the scientific debate. His article helps to frame the issue of life-cycle GHG emissions in a new way - in terms of net sequestration instead of gross benefits. I also appreciate his emphasis on indirect emissions from displaced food production - an issue policymakers should consider and begin to address.

The article fails to address the issue of permanence, however. Fossil fuels, once burned, cannot be put back into the ground (at least with current technology). Cleared land can be regrown, however. Searchinger's model seems to assume that land clearance is permanent, but, theoretically, we could use biofuels from crops to displace fossil fuels over the next, say, 30 years, while we transition to other technologies/fuels and then allow the land to return to its natural state, sequestering the carbon previously emitted. I'm not saying we can count on this happening or that clearing land for biofuels is a good idea, but it is a possibility that this article neglects. Conversely, we could stop using biofuels entirely, continue to burn fossil fuels at increasing rates, and, in 30 years, displaced people could clear the 10.8 million hectares anyway, releasing the stored carbon in spite of our efforts.

The issue of permanence and displacing fossil fuel use is one that should be addressed as this conversation moves forward.

amazingdrxFeb 13 2008 01:28 PM

"This makes the urgency around getting a federal low-carbon fuel standard all the greater."

The really low carbon transportation fuel doesn't come by the gallon or litre, it is measured by the kwh. Renewable electricity that is used to recharge a plugin hybrid ought to get a 10 cent per kwh subsidy for being renewable and a 10 cent per kwh subsidy for saving GHG and oil.

Russ FinleyFeb 13 2008 09:22 PM

If they are worse than fossil fuels, what is there to be thankful for?

A lot of people have become emotionally invested in the concept of biofuels. And let's face it, we are emotional creatures capable of rational thought, not the other way around.

1) We are in the middle of the sixth great extinction event. The destruction of the planet's biodiversity is directly correlated to the destruction of ecosystems, now commonly referred to as carbon sinks.

2) The second leading cause of global warming is from the destruction of carbon sinks, with Brazil and Indonesia being the number two and three emitters behind the United States and China.

3) All crop-based biofuels being produced today are exacerbating the destruction of those carbon sinks. The concept isn't simplistic. The concept is simple as the following graphic demonstrates:

There was an earlier article in Science that said the same thing:

Followed by one in the Journal of Atmospheric chemistry and physics:

The two most recent articles can be found below:

To get a feel for what this is going to do to the planet, visit this graphic:

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