The announcement of two Science papers (Fargione et al., 2008; Searchinger et al., 2008) calculating higher carbon dioxide emissions through changes in land use is making a lot of noise. But will the public get this travesty enough to force a change in federal policy on ethanol?

It didn't take these studies to wake up scientists and more progressive policy makers to the dangers of overemphasis on ethanol.

Yet a quick check on Technorati of responses to this news shows a lot of people still don't get it. Some bloggers gleefully have blamed environmentalists for going to town on ethanol use, but scientists (the great majority of whom are environmentalists, but not vice versa) have known better for a long time - some smart ones just got a couple of easy Science papers out of the hot political potato that biofuels production is becoming. The papers are highly complementary, and both expose the faulty math that has been done to promote ethanol production as "renewable" energy - which is not so renewable after all when rain forests and grasslands are destroyed to produce it.

Fargione et al. calculated actual carbon release due to land clearing in order to create more land for biofuel production, and Searchinger et al. produced a model which uses estimates of these numbers. Both methods produce the same conclusion: the worldwide ethanol frenzy, ostensibly about reducing greenhouse gas (GHG) emissions, will actually accelerate the production of atmospheric carbon dioxide through the destruction of ecosystems which have much higher carbon storage than the biofuels plants themselves do. This is not a problem of the future, but is currently happening, both directly and indirectly: either new land is cleared for biofuel production, or the conversion of current crop land (or animal-feed land) for biofuel forces creation of new crop land. The fallacy of this is most extreme in Indonesian peatlands, which Fargione et al. point out are huge carbon sinks, and thus liberating this carbon to grow palms for oil leaves us with a carbon debt that may not be repaid for over 800 years.

Searchinger et al.'s model, as all models do, must make numerous assumptions about the numbers that cannot necessarily be confirmed at this time. However, they take great pains to be conservative in their estimates of carbon released due to changing land use, and the logic in their introduction cannot be denied. They point out what is known from previous studies: the carbon cost of growing biofuel feedstocks, refining them into fuel, and then burning them, is no different from the carbon cost of oil. What supposedly swings the balance in favor of biofuels is that while they are growing they take up carbon from the atmosphere, while the burning of fossil fuels liberates previously sequestered carbon. Given that we know that land conversion means a lot less carbon sequestered in plants grown on the same acreage, the model is practically gratuitous.

So why the big push for "renewable" ethanol? It didn't come from environmentalists. It came from agribusiness, the huge corporations such as Archer Daniels Midland, who have the most to gain from this legislation. By declaring the production of ethanol "renewable," (not to mention running their ads on PBS), they have framed themselves as a company who cares about people and the environment. But the consequences of the ethanol rush would have been obvious to anyone formulating the policy. Simply, like most legislation we've seen over the last decade plus, this is all about money - specifically, taxpayer giveaways to huge corporations whose buddies happen to be running the government.

Given that once again we seem to have failed to find our magic energy bullet, then what is the solution? Are scientists who criticize various alternative energy sources on environmental grounds hopelessly naive? Not at all. They simply acknowledge that our range of solutions is quite a bit wider than that proposed by corporate giants who want all the taxpayers eggs in their industry's personal basket.


References

Fargione, J.,Hill, J., Tilman, D., Polasky, S., Hawthorne, P., 2008. Land clearing and the biofuel carbon debt. Science (in press).

Searchinger, T, Heimlich, R., Houghton, R. A. , Dong, F., Elobeid, A., Fabiosa, J., Tokgoz, S., Hayes, D., Yu, T. 2008. Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land use change. Science (in press).

Labels: biodiversity, ecology, environment, forests, politics