Biofuels Deemed a Greenhouse Threat By ELISABETH ROSENTHALPublished : February 8 , 2008 Almost all biofuels used today cause more greenhouse gas emissions than conventional fuels if the full emissions costs of producing these “ green ” fuels are taken into account , two studies being published Thursday have concluded . World View : Greg Winter and Libby Rosenthal discuss the downsides of biofuels . ( mp 3 ) The benefits of biofuels have come under increasing attack in recent months , as scientists took a closer look at the global environmental cost of their production . These latest studies , published in the prestigious journal Science , are likely to add to the controversy . These studies for the first time take a detailed , comprehensive look at the emissions effects of the huge amount of natural land that is being converted to cropland globally to support biofuels development . The destruction of natural ecosystems — whether rain forest in the tropics or grasslands in South America — not only releases greenhouse gases into the atmosphere when they are burned and plowed , but also deprives the planet of natural sponges to absorb carbon emissions . Cropland also absorbs far less carbon than the rain forests or even scrubland that it replaces . Together the two studies offer sweeping conclusions : It does not matter if it is rain forest or scrubland that is cleared , the greenhouse gas contribution is significant . More important , they discovered that , taken globally , the production of almost all biofuels resulted , directly or indirectly , intentionally or not , in new lands being cleared , either for food or fuel . “ When you take this into account , most of the biofuel that people are using or planning to use would probably increase greenhouse gasses substantially , ” said Timothy Searchinger , lead author of one of the studies and a researcher in environment and economics at Princeton University . “ Previously there ’ s been an accounting error : land use change has been left out of prior analysis . ” These plant - based fuels were originally billed as better than fossil fuels because the carbon released when they were burned was balanced by the carbon absorbed when the plants grew . But even that equation proved overly simplistic because the process of turning plants into fuels causes its own emissions — for refining and transport , for example . The clearance of grassland releases 93 times the amount of greenhouse gas that would be saved by the fuel made annually on that land , said Joseph Fargione , lead author of the second paper , and a scientist at the Nature Conservancy . “ So for the next 93 years you ’ re making climate change worse , just at the time when we need to be bringing down carbon emissions . ” The Intergovernment Panel on Climate Change has said that the world has to reverse the increase of greenhouse gas emissions by 2020 to avert disastrous environment consequences . In the wake of the new studies , a group of 10 of the United States ’ s most eminent ecologists and environmental biologists today sent a letter to President Bush and the speaker of the House , Nancy Pelosi , urging a reform of biofuels policies . “ We write to call your attention to recent research indicating that many anticipated biofuels will actually exacerbate global warming , ” the letter said . The European Union and a number of European countries have recently tried to address the land use issue with proposals stipulating that imported biofuels cannot come from land that was previously rain forest . But even with such restrictions in place , Dr . Searchinger ’ s study shows , the purchase of biofuels in Europe and the United States leads indirectly to the destruction of natural habitats far afield . For instance , if vegetable oil prices go up globally , as they have because of increased demand for biofuel crops , more new land is inevitably cleared as farmers in developing countries try to get in on the profits . So crops from old plantations go to Europe for biofuels , while new fields are cleared to feed people at home . Likewise , Dr . Fargione said that the dedication of so much cropland in the United States to growing corn for bioethanol had caused indirect land use changes far away . Previously , Midwestern farmers had alternated corn with soy in their fields , one year to the next . Now many grow only corn , meaning that soy has to be grown elsewhere . Increasingly , that elsewhere , Dr . Fargione said , is Brazil , on land that was previously forest or savanna . “ Brazilian farmers are planting more of the world ’ s soybeans — and they ’ re deforesting the Amazon to do it , ” he said . International environmental groups , including the United Nations , responded cautiously to the studies , saying that biofuels could still be useful . “ We don ’ t want a total public backlash that would prevent us from getting the potential benefits , ” said Nicholas Nuttall , spokesman for the United Nations Environment Program , who said the United Nations had recently created a new panel to study the evidence . “ There was an unfortunate effort to dress up biofuels as the silver bullet of climate change , ” he said . “ We fully believe that if biofuels are to be part of the solution rather than part of the problem , there urgently needs to be better sustainability criterion . ” The European Union has set a target that countries use 5 . 75 percent biofuel for transport by the end of 2008 . Proposals in the United States energy package would require that 15 percent of all transport fuels be made from biofuel by 2022 . To reach these goals , biofuels production is heavily subsidized at many levels on both continents , supporting a burgeoning global industry . Syngenta , the Swiss agricultural giant , announced Thursday that its annual profits had risen 75 percent in the last year , in part because of rising demand for biofuels . Industry groups , like the Renewable Fuels Association , immediately attacked the new studies as “ simplistic , ” failing “ to put the issue into context . ” “ While it is important to analyze the climate change consequences of differing energy strategies , we must all remember where we are today , how world demand for liquid fuels is growing , and what the realistic alternatives are to meet those growing demands , ” said Bob Dineen , the group ’ s director , in a statement following the Science reports ’ release . “ Biofuels like ethanol are the only tool readily available that can begin to address the challenges of energy security and environmental protection , ” he said . The European Biodiesel Board says that biodiesel reduces greenhouse gasses by 50 to 95 percent compared to conventional fuel , and has other advantages as well , like providing new income for farmers and energy security for Europe in the face of rising global oil prices and shrinking supply . But the papers published Thursday suggested that , if land use is taken into account , biofuels may not provide all the benefits once anticipated . Dr . Searchinger said the only possible exception he could see for now was sugar cane grown in Brazil , which take relatively little energy to grow and is readily refined into fuel . He added that governments should quickly turn their attention to developing biofuels that did not require cropping , such as those from agricultural waste products . “ This land use problem is not just a secondary effect — it was often just a footnote in prior papers , ”. “ It is major . The comparison with fossil fuels is going to be adverse for virtually all biofuels on cropland . ”