About those two studies dissing biofuels

I’m sure you’ve already read about them at the NYT or Grist. But where else can you get the links to the (abstracts of the) studies themselves?

  1. Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change
  2. Land Clearing and the Biofuel Carbon Debt

As for commentary, what is there to say after “Doh!” and “Duh!” As I’ve written:

Biofuels from most food crops or from newly deforested lands do not provide a significant net decrease in greenhouse gas emissions — and some may cause a net increase.

The studies do bring some rock-solid new analysis to explaining just how counterproductive most biofuels are from a climate perspective. Their abstracts say it all:

  1. Most prior studies have found that substituting biofuels for gasoline will reduce greenhouse gases because biofuels sequester carbon through the growth of the feedstock. These analyses have failed to count the carbon emissions that occur as farmers worldwide respond to higher prices and convert forest and grassland to new cropland to replace the grain (or cropland) diverted to biofuels. Using a worldwide agricultural model to estimate emissions from land use change, we found that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50%. This result raises concerns about large biofuel mandates and highlights the value of using waste products.
  2. Increasing energy use, climate change, and carbon dioxide (CO2) emissions from fossil fuels make switching to low-carbon fuels a high priority. Biofuels are a potential low-carbon energy source, but whether biofuels offer carbon savings depends on how they are produced. Converting rainforests, peatlands, savannas, or grasslands to produce food-based biofuels 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, 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.

Time for a new biofuels policy.


16 Responses to About those two studies dissing biofuels

  1. Earl Killian says:

    If these studies hold up, won’t the Center for American Progress need to revise its energy policies? For example, the energy chapter of Progressive Growth: CAP’s Economic Plan for the Next Administration suggests cellulosic ethanol from “dedicated crops such as switchgrass” among other things. The “Small Farm Owner” example is exactly what Searchinger warns against (the conversion of cropland to switchgrass, not the wind turbines). In general CAP’s energy chapter seems to highlight switchgrass as a positive alternative to corn, but in light of these papers they should both be be considered unwise. Calls for cellulosic ethanol should be limited to waste feedstock, and not “dedicated crops”. Tilman’s LIHD might be an exception (though Tilman’s numbers suggest electricity might be better than ethanol for LIHD).

  2. Peter Kelley says:

    We’ve been taking a look at this with the United Nations Foundation. Their blogger Matt Cordell wrote yesterday, “Judging renewable fuels on a snapshot of what they’re capable of now is like judging aviation based on the Wright brothers’ flyer. Within 65 years, we’d broken the sound barrier and landed on the moon. In the last five years alone, we’ve been able to increase switchgrass yields by 50 percent. Everyday, less and less land can be used for more and more fuel, promising to reduce the carbon footprint dramatically. In less than a decade, it is highly likely that converting that grass to fuel will become economically viable and therefore widespread. Similar technology could be used to produce fuel from waste like yard clippings, brush, animal fats, scrap paper, algae, and sawdust — all of which requires no additional land use. And that’s only the tip of the iceberg.”

    More at

  3. Ronald says:

    All of this has been discussed before, but 30 years ago. I remember having these discussions in college in the late 1970’s. We were up on the then latest ideas about whether it made economic or energy sense and we came to the conclusion that it didn’t make sense to do. Now here we are. This is just a touch of madness.

    Let’s not forget that the reason we do ethanol is not for global warming, but misguided energy policy of pres. Bush to reduce dependence on oil.

    My view of the whole thing is we don’t do enough to replace fuel oil that is used to heat homes and businesses in the northeast and other places and use that as diesel fuel to power vehicles and use solid biofuels and biomass to do the building heating and for industrial processes.

    The goal should be to use solid biomass to heat buildings and industrial heat processes because stationary units can be built to do it.

    The goal for mobile vehicles would be to burn liquids. Liquid fossil fuels are to valuable to be used for building heating.

    If we did that there would be no need to process biomass into liquid biofuels.

    The easy way to break down cellulose biomass is with fire.

    Natural gas (methane gas) can also be compressed and used as a vehicle fuel which also would be easier than breaking cellulose biomass into a liquid biofuel.

  4. RhapsodyInGlue says:

    Another issue I don’t believe these papers address is that they might be making the wrong comparison. At least here in North America, the new sources of oil that are coming online are “unconventional”, as in tar sands and potentially oil shale. These have a much higher carbon footprint. So if switchgrass “only” has a 50% penalty, it still is probably better than tar sands.

    Of course another way of dealing with the situation would be to dramatically decrease beef production. That would free up a lot of existing cropland… with the big added bonus of helping out a lot with methane. Not to mention health benefits.

    I wonder if there would be any hope of gradually mixing soy protein or even some other animal meat (pork and/or turkey perhaps) in with the tons of ground beef that is consumed every year. One would need a clever marketing campaign… McDonald’s new 100% Beif(tm) burgers.

  5. Andy says:

    Restoring native grassland on the U.S’s millions of acres of CRP (Conservation Reserve Program) lands would be a very positive step in producing a GHG negative biofuel source. Native grasslands (prairies) do produce very high biomass without fertilization or irrigation and do incorporate much carbon deep into the soil and can be cut once a year without damage. Simply restoring native prairie would be ghg negative; biofuel production from native hay would be more so. Currently CRP lands are idled and planted with a single or two species of grass, often not native. The do not incorporate carbon into the soil nor do they produce nearly the biomass as our native grassland which can contain over 100 species of plants on a single acre and act as a complex organism that is self-fertilizing and tilth increasing organism. However, the seed source and know how are lacking if such a large effort at prairie restoration were to be made today.

  6. charlie says:

    What these studies show is that the import duty on imported ethanol from Brazil is an environmentally friendly idea.

  7. Michael says:

    Some of the comments here indicate that there is still a biofuel “obsession” among people who believe themselves to be environmentalists or concerned about climate change.

    WAKE UP!!!: Electrify transportation! Electric motors are 3 times as efficient as internal combustion. Solar panels and wind turbines are coming down in price and about one or two orders of magnitude more efficient at turning natural energy into mechanical energy.

    Biofuels may have a marginal role but should be heavily regulated to make sure they don’t exhaust the soil, water resources, etc. It is most often better to use biomass to generate electricity or heat than turn them into biofuels. The biofuel blinders that some people wear, thinking that they are helping the planet, has set a market up that is dangerous for the planet.

    So: WAKE UP!!!

  8. David B. Benson says:

    Of course, one could attempt to keep up regarding bioenergy by following

    where today’s post has some quite intereting news regarding the trend in coal prices, leading to the idea of replacing (some) use of coal by biomass.

  9. David B. Benson says:

    And an earlier entry in which a new process has been ceveloped to produce ethanol for one dollar per gallon from any biomass whatsoever: clarification sludge, animal wastes, forestry wastes, etc. No cropland required.

    So much for the ‘no biofuels’ argument…

  10. Paul K says:

    The question is what if any taxpayer provided grants, subsidies or credits should be given to any technologies on the horizon. Corn to fuel is heavily subsidized. Those who blame President Bush are in error. He favors switch grass. Those who want to get off corn had better talk to Democratic leaders Harkin and Durbin and Obama and Clinton and the governors and representatives of every corn belt state. There is only one leader who has been consistently and openly opposed to corn ethanol subsidies. That leader is John McCain.

  11. Earl Killian says:

    David B. Benton, when I looked at to find the source of your earlier 1400 EJ claim, I found they cited an IEA report, which I read. However, the IEA thought 200-400 EJ was the likely amount (the full range was 40-1100 EJ with 1100 EJ being “most optimal”, or the way I interpret such things, “most unlikely”. The IEA’s 200-400 would need to be reevaluated in light of the two articles just published in Science.

    Since the sunlight reaching Earth is 2780 times even 1400 EJ, it seems that sunlight is a better place to look for energy (as I argued on 1/17 in reply to your post then).

    Yes, waste products can be converted to ethanol, and Coskata’s technology may be a good way to do that. And using waste biomass is a good thing compared to dedicated biofuel crops, provided that the ash content of the biomass is returned to the fields to prevent depletion. But if you look up the Ag waste biomass currently available in the U.S. according to NREL, you find it is something like 157 million tons. That’s nice, but it is only enough to make gasoline into E08. I’m all for it in the short-term, but we should recognize that it isn’t the long-term answer we’re looking for.

  12. David B. Benson says:

    Earl Killian — Since that IEA report, researches in The Netherlands have further studied the matter. They conclude that the bioenergy potential of the entire planet is over 1500 exajoules, after deducting the land required for human and animal food and for forestry.

    As reasonable estimate for the energy needs in 2050 is about 800 exajoules. I estimate that about half that will be provided, world-wide via biomass. THe United States is blessed with great potential for both solar and wind. Other countries are not so fortunate, but have a bioenergy potential considerably larger than that of the United States.

    In general, my adivce is to keep reading Biopact, daily, to see what is coming. As for ag waste potential, this might leave out forestry wastes, but certainly leaves out municiple wastes. However, North America’s biomass potential is exceed by but that of South America and also by Africa’s. So maybe importing some will be part of an energy solution for awhile.

  13. Jonas says:

    This debate was over before these papers were published.

    If you use the original biomass as a biomass feedstock instead of burning it (as is done currently), your carbon debt from above ground biomass is gone.

    The next step is to create carbon negative biofuel systems, by stuffing the soil with biochar.

    In short, biofuels are the most effective tool in the climate fight. No other form of renewable energy can go carbon-negative. Bioenergy can.

    Time for a new biofuel policy.

  14. Jonas says:

    By the way, I’m surprised to read that someone who is working on climate solutions, hasn’t referred extensively to bio-energy with carbon storage.

    Had he been an expert, he would know that you can get back to pre-industrial CO2 levels by implementing biomass + CCS systems.

    Lifecycle CO2 emissions per kilowatthour from different energy sources:

    -coal: +850grams of CO2eq/kWh
    -gas: +350grams of CO2eq/kWh
    -coal + CCS: +150grams of CO2eq/kWh
    -solar photovoltaic: +100grams of CO2eq/kWh
    -wind: +30grams of CO2eq/kWh
    -non-CCS biomass: +30grams of CO2eq/kWh
    -nuclear: +20grams of CO2eq/kWh
    -hydro: +10grams of CO2eq/kWh
    -biomass + CCS (e.g. in an IGCC plant): -1000grams of CO2eq/kWh (yes, that’s *minus*, hence “negative emissions”)

    So there. Biomass+CCS cleans up the atmosphere and removes CO2 from the past. It’s the most radical tool in the climate fight. The only solution that has a reasonable chance of making an impact.

    How come the author of this blog isn’t aware of negative emissions systems?

  15. Joe says:

    I am quite aware of it and have been for over a decade. That’s one reason I’m not a fan of biofuels. It’s not a good use of biomass.