NEW YORK, USA, 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.
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 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.
“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.
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 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.
Nicholas Nuttall, spokesman for the United Nations Environment Program, summarized the new stand of the UN on biofuels. He said, “There was an unfortunate effort to dress up biofuels as the silver bullet to defeat climate change.”