It would be interesting and informative, i think, if we could generate a world map of all 'abandoned agricultural lands planted with perennials' that create this so-called 'feedstock uptake credit' (greenhouse gas credit) that have the potential to be populated with the appropriate biomass. These techniques and approaches sound good in theory, but what is the overall potential when all areas are accounted for? Is there cost-effective access to each area? Does the ethanol produced in this way satisfy a significant portion of anticipated demand? What about the infrastructure to distribute?

Joseph

not quite sure whether your being sarcastic or not. But our countries desire to farm everything from an industrial model and lack of foresight for the damage doing this can cause is insane.

biofuel from agro-crops are bad, however, i'd say they are/were necessary to develop the demand and infrastructure for 2nd generation biofuels to come online.

Our legislative bills that provide support for bio-fuels should at this point have nothing to do with subsidizing agro-crops. If this country continues its increase with these 1st gen fuels points where our run-off concentrates like the gulf of mexico will be irrecoverable.

Our country needs to set an example and utilize our waste streams and how bout maybe getting these scientific panels to provide some real energy balance assessments prior to the development of an industry not after is starts to gain steam.

The only type of biofuel that can be produced both sustainably and cost-effectively at industrial scales from cellulosic wastes *today* is biogas. Second-generation bioethanol and biodiesel are still stuck in the laboratory and/or pilot projects.

Scrub out the H2S and CO2 and you have biomethane, which can be fed into the natural gas distribution grid. Methane is a great fuel for internal combustion engines and should become much more viable for mobile applications (i.e. cars) once adsorption tanks (ANG) can replace the heavy and expensive CNG tanks and, sharply reduce the pressure at which the gaseous fuel needs to be stored.

Physical (LNG) and chemical liquefaction (GTL, DME) are of course possible, but I'll wager keeping the fuel as close as possible to its natural state will prove to be more efficient.

The studies are not very interesting, because you can offset this carbon debt very easily by using the original biomass (e.g. from a wood land) itself as a biofuel feedstock. Why burn this wood when you can use it to produce renewable energy?

This is already being done in the field and the development of modular pyrolysis plants makes it feasible on a larger scale.

Case closed (at least when it comes to the above ground biomass).

Check more here on second and third generation land use practises:

New land use techniques boost benefits of biofuels

I'm dubious about some of their assumptions - did they assume all forests were young? - which affects details of their conclusion. But the philosophy is still valid: the final affect of changes like an increase in biofuel ethanol from corn is complicated by the interactions in the global economy.

Brian, please man, the amount of biofuels produced from crops grown on land that used to be pristine forests is marginal. The green lobby has tried to make it look as if all biofuels are destroying rainforests. Nothing is further from the truth. The vast bulk is grown on low carbon land.

So don't push this false message please. It is damaging the case of conservationists.

Moreover, don't forget that new land use techniques based on biochar actually stuff soils full of carbon.

Jonas,
Maybe I am confused, but I think we are saying the same thing.

I am in no way saying that there is not a problem with deforestation and land use. I am no way saying that conservationists and all green-thinking folks should not continue to push and demand change.

I am saying we need to look at the reality of the situation we are in and make changes from within.

Anyway, I'm not sure I understand your concern or maybe my point wasn't clear. I at least like the discussion.

@ HealthyBreeze -

I think you may be confusing two issues here. Yes, crops like miscanthus do absorb CO2 more quickly than a forest will. However, the whole point of planting the crop is to turn it into fuel that then gets burnt. Ideally, you end up with a perfectly closed loop in which no fossil hydrocarbons are used in e.g. the agriculture. Even then, you need to consider how long the cycle is (e.g. annual) and what fraction of the cycle the carbon spends in the atmosphere (guesstimate: 40-60%). Of course, such cycle considerations only refer to the integral carbon mass balance, not individual atoms.

By contrast, the carbon in a forest has a much longer cycle time of decades to centuries, depending on type and location. Growth is multi-annual but fairly consistent. A mature forest with stable total biomass will typically re-sequester the carbon mass released by the natural decay of dead wood within one year. So, figure the atmospheric fraction of the cycle amounts to just a few percent of total cycle duration. The fraction is higher for tropical rain forests, but so is the total carbon mass in the cycle per square acre.

A sudden release of carbon dioxide due to e.g. a forest fire means it remains in the atmosphere for decades, a timescale that may be long enough to have an impact on the climate. Worse, if the topsoil is lost to erosion after the fire, the forest cover will not return and the original emissions are just as permanent as if you had dug up coal and burnt that.

If you clear forest lands to make room for crops, the calculation becomes a little more involved. The new crops will sequester some atmospheric CO2 for part of the year. However, the total carbon mass in the new crop-based cycle will be substantially smaller than that in the original forest cycle. Therefore, the net effect is that the vast majority of the carbon sequestered by the forest cycle is permanently lost to the atmosphere.

Paleoclimatology suggests that the emergence of crop farming at the end of the last ice age coincided with a stabilization of the climate. Later on, vast tracts of forest were cleared in e.g. Europe to build ships and make room for fields and meadows. Spain is a prime example. What isn't really clear yet is how the climatic changes due to ice ages (which are probably caused by celestial mechanics) and those due to relatively rapid regional deforestation relate to one another in terms of scale and dynamics.

I've been researching and writing on biofuels sustainability issues intensively for the past couple of years. I agree with Brian it is world agriculture as a whole we need to consider, not just biofuels. The land use displacement issue, to my mind, is the most complex. Here a small thought experiment is valuable. Consider the system with no biofuels - Would the disturbance of forest and grassland soils and carbon release never take place? There is no way to assert this, since growing demand for food, feed and fiber will push onto the same lands, though perhaps a few years later.

So then how do we preserve this carbon? Clearly we must make a profitable market for farm and forest carbon that is competitive with other uses. Meanwhile we should look at where bioenergy can promote bio-carbon sequestration by adding a value stream. That logically points to perennial grass and tree crops that sequester more in the roots than is released in bioenergy production and use. Putting together bioenergy and carbon revenue streams could enable production on lands that might be marginal for bioenergy alone.

Bottom line - High oil prices plus energy insecurity will continue to drive biofuels whether they are grown sustainably or not. We need policies such as low carbon fuel standards to drive toward sustainability.

I figured that a state the size of Kansas could grown enough biomass in the form of corn stalks and wheat straw to provide 1/3 out our personal transportation fuel needs.

This is after they harvest the corn and wheat for food. We have plenty of farm land in the U.S. and we grow plenty of grain. Now, just use the grain STALKS for fuel and get on with it!

These studies amaze me, it seems when we compare biofuels we compare it to virgin native forest and of course it's co2 uptake is going to be less, we should only compare Biofuels to refined gasoline use. I live in Canada and I am familiar with the oil sands production, there is no way anyone can convince me that 1000's of acres of surface extraction, huge lakes of water effluent that can never be used again (creating a shortage for farmers) and many megawatts of power from coal to extract the oil is better than acres of biofuel growth (mixed with native plants and trees). Oil also needs to be refined to gasoline again using huge amounts of power.
Biofuels are 'part' of the mix and we have to start somewhere, cellulose production is of course the way to go when ready but it takes many years of design and construction to build Biofuel plants, we can impove them and their feedstock over time.
Most of our food is shipped using fuel, it's the price of gasoline that raises the price of food not the cost of corn, the farmers don't get the lion share.

The basic point of these studies is correct: the development of biofuels can cause changes in land use that lead to relatively large emissions of carbon from soils and biomass. Indeed, this basic finding has been known, and quantified, for almost 20 years. The Searchinger et al. paper does do something relatively new: it uses an agricultural model to estimate global changes in production and consumption, the first step in estimating emissions due to land use change. (It also has a detailed treatment of changes in land use by type of ecosystem.) However, both papers suffer three serious general deficiencies, apart from whatever legitimate questions one might have about details of the modeling.

First, the studies do not have a complete conceptual treatment of what happens over time. Most importantly, they ignore the carbon sequestration that will tend to happen when the biofuel programs end and the land-use changes that occurred at the start of the program are reversed. Related to this, the explicit or implicit treatment of the timing of impacts in the studies – namely, that there is no distinction to be made between climate impacts that occur today and climate impacts that occur many decades from now – is not economically realistic.

Second, changes in land use affect much more than just carbon stocks in soils and biomass: they also affect albedo, hydrodynamics, the nitrogen cycle, dust emissions, and more. All of these omitted factors can have significant effects on climate, and not all of these effects are “bad” (i.e., warming). Without doing a comprehensive analysis of all of the climate-relevant effects of land-use change, it is not possible to make general statements about the effects of land-use change on climate.

Third, both studies add emissions from land-use change to emissions from the rest of the lifecycle of biofuels, and then make general statements about how considering land-use change affects total emissions from and the overall desirability of biofuels. However, there is as yet no remotely good model of emissions from the “rest” of the life cycle of biofuels, and as a result it is not possible to make any definitive statements about the overall impact of considering land-use change emissions in lifecycle analysis.

In sum, these studies highlight an important (and generally well known) effect of the development of biofuels, but leave out a great many important factors, and do not tell us anything definitive about the overall impact of biofuels on climate.

Mark Delucchi
Institute of Transportation Studies
University of California, Davis
www.its.ucdavis.edu/people/faculty/delucchi

The recently "Low Carbon Fuel Standard" report, coauthored by Alex Farrell and Daniel Sperling,
Seemed to express some frustration with the difficultly of factoring in land use impacts.

_

Additionally, I hate to sound rude.
But Nitrogen emissions, and the decreased Albedo caused by biofuels crops seem like they would only increase the harm caused by biofuels production.
www.treehugger.com/files/2006/12/planting_trees.php
greyfalcon.net/n2o.png

As well as counting the emissions reduction when ENDING a biofuels production program seems to be a little flimsy of a qualifying part left out.
(Especially since simply reverting back to what was previously there 10 years later, wouldn't account for the compounded effect of warming feedbacks since then.)

And while models might not be perfect to date, it certainly does question the wisdom of rushing forward with ambitious biofuels mandates when there is a reasonable doubt that they could significantly cause more harm than good.