TY - JOUR
T1 - Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land-use change
AU - Searchinger, Timothy
AU - Heimlich, Ralph
AU - Houghton, R. A.
AU - Dong, Fengxia
AU - Elobeid, Amani
AU - Fabiosa, Jacinto
AU - Tokgoz, Simla
AU - Hayes, Dermot
AU - Yu, Tun Hsiang
PY - 2008/2/29
Y1 - 2008/2/29
N2 - 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.
AB - 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.
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U2 - 10.1126/science.1151861
DO - 10.1126/science.1151861
M3 - Article
C2 - 18258860
AN - SCOPUS:40049104506
SN - 0036-8075
VL - 319
SP - 1238
EP - 1240
JO - Science
JF - Science
IS - 5867
ER -