Nathanael Greene's Blog
Giving voice to my biofuels birthday wishes
March 12, 2008
Posted by Nathanael Greene in Moving Beyond Oil , Solving Global Warming
So today is my birthday, and I have been struck dumb by a case of laryngitis. It seems somehow appropriate for someone who spends so much of his time talking. Of course at home, where I'm the lone male, nobody much respects my authority anyway, so not that much has changed--only now instead of my girls pretending they can't hear me, they really can't. In any case, it's all enough to make one a little philosophical. I haven't had more than a few seconds to rub together for the last few weeks, so given my current predicament, blogging seems like a good way to... express myself today.
I spent Monday at the Ecological Society of America's Conference on the Ecological Dimensions of Biofuels. It was an interesting, but ultimately frustrating day. While the stated objective of the conference was to help policy makers by bringing the best science to the table, there was a real dearth of synthesis and application of all the great "applied science" that was presented.
The presentation largely fell into two groups--studies of how to do biofuels wrong and studies of how to do biofuels right. What was missing was studies of how to get farmers and biofuel refiners to actually do what is right and not do is wrong. Thanks to the hard work of Amelia Nuding, NRDC presented this poster [large file designed to print out on 4'x6' format!] focusing on the ESIA07, but beyond that and a few references to the volumes required under the new RFS, nobody focused on the environmental safeguards and GHG standards. But this is where scientists need to get most involved! How should we implement these requirements? What will they accomplish? Is that enough? How do we go further? These are big questions, I know, but this is where ESA and its members need to engage.
As I listened to presentations that involved economics, those that were starting to incorporate the thinking in the two Science articles, and those worried about biofuels exacerbating the current impacts of agriculture and forestry, an important question formed in my head. I might even go so far as to call it a paradox (I said I was feeling philosophical, and in any case, it's my birthday and I can't talk so cut me some slack). Here it is: The best tools we have for understanding the impact of technologies, policies, and other changes to large complicated systems like markets assess the change in the system when there is a small change involving whatever is the subject of our analysis. So for example, Searchinger et al. tried to estimate the marginal change in GHG emissions in the global land-use system that would be caused by the production of one gallon of ethanol from corn land. But one thing that working on stopping global warming has taught us is that we cannot achieve a sustainable future by changing just one part of the system. In part, this is because no one method of reducing GHG emissions can be large enough. But, some might argue, looking at marginal analysis can at least tell us whether something is part of the solution or part of the problem--is it moving us marginally in the right direction? However, what I've started to ask myself is if the system needs a major overhaul--a step function change--could options that look negative on a marginal basis in the context of the current system actually be positive in the context of a rationalized system. And if the answer is, as I suspect, yes, then how do we manage the small part of the system while working on the major overhaul.
To be a bit more concrete, given the dynamics that Tim Searchinger has identified, biofuel produced from prime agricultural land that displace food and feed production are at least not as good as we had hoped and probably bad for the climate. But this is only true in the context of the current global system around deforestation, or more accurately, the lack of a system. To stop global warming, we eventually need to stop deforestation especially in the tropics, and if we can do that, then from climate perspective biofuels from prime ag land goes back to whatever level of benefits we think they have now. (Impact on food prices is another matter that still would need to be addressed.) So do we stop producing biofuels on prime agricultural land until we solve deforestation? Do we have time to sequence all of our solutions perfectly?
Fortunately, we don't have to wait for biofuels. There are significant amounts of biomass out there that doesn't compete with food, feed, or fiber for land and much more that can be developed. A number of presenters at the ESA conference mentioned winter cover crops, and one questioner from the floor (Prof. Scott Swinton from Michigan State) actually raised the question of what it would take to get farmers to plant cover crops. According to Prof. Swinton there isn't great data on cover crops, but on ERS's website, I did see a quick reference to 4% of harvest cropland being double cropped in 2002. That's about 13 million acres. From another conversation, with a grad student, I understand that current yields from cover crops are pretty low, maybe about 1 ton per year. If we could increase cover crops to, say, 1/3 of all crop land (~113 million acres) and increase yields to, say, 3 tons, then we have about 300 million tons of material that did not interfere with food, feed, or fiber. That's more than enough to meet the current RFS requirements for advanced biofuels.
Now today, cover crops can provide significant environmental benefits helping to keep the soil in place and absorbing excess nutrients that would otherwise runoff (e.g. see this presentation [big PDF] on biofuels and water quality in the Chesapeake Bay watershed and this study by Kim and Dale, which shows how cover crops allow for more residue removal). Can we figure out how to dramatically increase the number of acres under cover crops and increase the yield from the winter crops, and preserve these benefits?
Add in ag residues that are really residues and not needed for the soil or nutrients and forest residues from privately owned wood plantations that are really residues, and recapture and revitalize some ag lands that have been degraded and left fallow, and you start having a significant supply of truly low-carbon biomass that doesn't have any land-use carbon debt (and may actually provide a host of environmental benefits if done right). There is certainly enough to launch the cellulosic biofuels industry, while we figure out how to solve deforestation.
[Side bar: I've heard from two sources now that corn cob removal may actually be purely good for the land. Something about these big, slow to degrade, chunks of biomass aren't great for the soil and also are a significant source of neutral runoff. I understand that some studies are underway, but if anyone has more information on this, I'm all ears (pun intended). At about 0.65 tons per acre, collecting cobs from all our corn land would produce over 50 million tons of biomass. At 100 gallons per ton, that 5 billion gallons.]
So how do we get farmers and biofuels refiners to build an industry around this type of material? Well, we develop rigorous regulations for the RFS that factor in land-use emission, using the best science, as the law requires, and we enforce the environmental safeguards as the law requires. We probably also need some new farm bill programs and to shift our current biofuels tax credits to help farmers start to grow and collect this type biomass and encourage biofuels producers to go our and source it.
A lot of folks think that getting good biofuels is going to be a lot harder in light of the indirect land-use emissions. We can no longer assume that all we have to do is convince farmers to stop growing commodity crops and start growing energy crops. But the reality is that was never going to be an easy sell and these alternative ways of integrating biomass production into food, feed, and fiber production are not likely to be any tougher.
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- Nathanael Greene
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Comments
Kim Ranney — Mar 12 2008 05:28 PM
Happy birthday, Nathanael! I hope you get your voice back.
Patrick Mazza — Mar 14 2008 02:10 PM
As you note, there is a larger systemic framework around land issues. One thought experiment is to ask - If biofuels were taken out of the picture, would the tropical forests and grasslands that are the focus of the Science studies not be disturbed? Or would the world's growing food, fiber and feed demands eventually cause carbon-releasing land conversions anyway? It is hard to argue against the latter. The timing might be on a somewhat longer scale, but the climate impact would be the same - and perhaps worse since there would not even be any fossil fuel displacement from biofuels.
So we need to place biofuels growth in a broader global carbon framework that provides solid incentives for preserving and growing soil carbon. If we really need to bring carbon dioxide concentrations in the atmosphere back to 300-350 ppm as Jim Hansen suggests, synergistic systems that grow bioenergy and biocarbon while enhancing agricultural productivity are going to be crucial to climate stabilization.
I draw out these themes in a series I am doing for Climate Solutions Journal, "Common Sense on Biofuels,"
http://climatesolutions.org/?s=journal&aid=94
http://climatesolutions.org/?s=journal&aid=95
Ethan Davis — Mar 18 2008 10:33 AM
I think ultimately Searchinger and other biofuel critics look only at worst case scenarios for biofuels, and leave out more progressive feedstock pathways that could be integrated within current agricultural practices so that both food and fuel production can be realized. Thus no new land would be converted, and the indirect ghg emissions would be zero. But, an important point that should be taken away from all this, is that biofuels can be more damaging than the fossil fuels they replace if we are not careful. That idea is entirely correct, and if we care about sustainability and not just security and independence, it is critically important to have honest emission counting.
But more important than supporting or denouncing advocates and critics of biofuels is to listen to both sides and address what are frequently valid points. Towards this end, any scenario that converts unmanaged lands to energy or food crops, or converts food crops to energy crops, poses serious sustainability challenges in terms of habitat destruction and ghg emissions.
But these aren't the only feedstock sources. It is possible to recover waste streams, (about 1 billion tons which could displace roughly 1/3 of our fuel demand); use double cropping; develop new crops that maximize food and cellulosic biomass; and co-produce food and fuels with protein recovery. Moreover, if perennial grasses were used instead of corn to feed livestock, and the residues were recovered for biofuels, this would dramatically increase soil C sequestration, an important and oft overlooked point. SOC storage can be a very significant ghg emission reduction in the life cycle of biofuels, but it is frequently overlooked.
That said, it is possible to produce food and fuel production with little to no increase in the managed land base, but this would require large changes in our agricultural system, much more efficient cars and transportation methods (mass transit), and major changes in our energy system. Thus, while possible it would be difficult, and if these changes are not made, then unsustainable biofuel production patterns like those envisioned by Searchinger will come to fruition. Thus biofuels are both a false hope and viable alternative, either way, it's up to us.
Patrick Mazza — Mar 19 2008 03:11 PM
Interestingly, neither Searchinger nor Fargione leave out the more sustainable pathways towards biofuels in their articles - though reading the headlines one could easily miss that. In part 1 of my series linked above, I note where the studies are pointing in terms of sustainable feedstocks.