Ethanol

Ethanol is a type of alcohol which burns and can be used in various types of gasoline engines. Ethanol is made from the sugars found in grains, such as corn, rapeseed, sorghum, and wheat, as well as potato skins, rice, sugar cane, and sugar beets. These plants and vegetables can typically also be eaten by people and are therefore a limited and valuable resource. With millions of starving people in the world, the use of edible crops for fuel production raises ethical as well as economic questions such as "How many poor people should starve so that people with lots of money can drive SUVs?"

New biotechnologies are developing ways to use the rapid growth of algae to produce ethanol directly. Algae can produce more oil than typical plants such as corn or rapeseed. Perhaps more important for the environment is that algae can be grown on land that is unsuitable for growing most crops. Algae are grown using sunlight and CO2. The use of CO2 for algal growth makes algae a fuel source that has no carbon footprint. As algae grow, they remove CO2 from the atmosphere.