Carbon debt of ethanol

[kristopher]

Science 29 February 2008:
Vol. 319. no. 5867, pp. 1238 - 1240
DOI: 10.1126/science.1151861


Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change
Timothy Searchinger,1* Ralph Heimlich,2 R. A. Houghton,3 Fengxia Dong,4 Amani Elobeid,4 Jacinto Fabiosa,4 Simla Tokgoz,4 Dermot Hayes,4 Tun-Hsiang Yu4

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. By 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.

[Statistical]

1. ethanol is a joke for everyone except those growing corn and making the magic green car juice.

Of course the ethanol lobby is insanely powerful so don't except that to change.

One example. As bad as ethanol is ethanol from corn is the worst possible method to make it. Sugar is about twice as efficient.
It is legal to import raw sugar w/o excess taxes for consumption. If you import it for making ethanol (at about half the cost of corn ethanol) it is subject to a 145% import tariff.

[lefthandedlefty]

3. Ethanol might be bad but

I love used vegtable and used motor oil in my diesels they seem to like it also.

[TheCoxwain]

2. Ethanol has low energy density ( fewer K joules per unit) .. and the worst part is that it is

Hygroscopic and will mix with water in any ratio .... you can imagine the consequences


Ethanol is a bad idea