[ 119 ] Earth and Space Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Refer to the following passage to answer the next four questions. As the world searches for alternatives to petroleum, corn-based ethanol and other biofuels derived from organic material have been considered as the perfect answer to transportation fuel problems. In fact, a U.S. government energy bill mandates that over 30 billion gallons of biofuels a year be used by the year 2020. However, separate studies released by the Nature Conservancy and Ivy League institutions reveal that ethanol may not be the best answer in the fight against global warming. They say biofuels could make things worse. Biofuel crops, such as corn and sugarcane, remove carbon from Earth’s atmosphere while they are growing. When biofuels are burned, they emit fewer greenhouse gases than fossil fuels like coal or oil. This makes biofuels almost carbon-neutral. However, studies are showing that ethanol could be even more dangerous for the environment than fossil fuels. The Ivy League study noted that clearing previously untouched land to grow biofuel crops releases long-contained carbon into the atmosphere. While planting biofuel crops in already tilled land is all right, the problem arises when farmers disturb new land to grow more sugarcane or corn. Additionally, food and feed crops are being displaced by biofuel crops. The Nature Conservancy warns that “converting rainforests, peat lands, savannas, or grasslands to produce biofuels in Brazil, Southeast Asia and the United States creates a ‘biofuel carbon debt’ by releasing 17 to 420 times more carbon dioxide than the fossil fuels they replace.” Other negative effects include the extreme amounts of water needed for irrigation, runoffs from pesticides and fertilizers, and the natural gas used to make the fertilizers that adds to the carbon deficit. Are the claims in the article from reliable sources? Are the claims in the article verified with supporting data?