Recently there has been a lot of interest in using plants as fuels to replace fossil fuels like gasoline and diesel that contribute greenhouse gases to the atmosphere, warming the planet.

These plant-based fuels, called biofuels, are typically produced from agricultural crops. The are two main types of biofuels: ethanol and biodiesel. Ethanol is typically made from corn and sugar cane, while biodiesel is made from the fruit of palm trees (more about palm oil), soybeans (more about soy), and canola (also called rapeseed).

While biofuels produced from agricultural crops can generate less pollution and greenhouse gas emissions than conventional fossil fuels, in practice, scientists are finding that some are causing environmental problems. Biofuels may also be hurting the poor. The reason is largely economic.

Now that traditional food crops are being used for the production of energy, there is increased demand for such crops, translating to higher prices. While higher prices may be good for some farmers who receive more money for the crops they grow, consumers have to pay more for food. In poor countries, where people have very little money, it means that many go hungry. In 2007 and 2008 several countries saw protests and riots by people who could not afford to pay higher prices for food.

Higher prices for crops is also causing other problems. To take advantage of higher prices, farmers all over the world are converting land for crop production. With most of the land in North America and Europe already used for farming, agriculture is expanding in tropical places, especially in Brazil and Indonesia, where there are still large areas suitable for new agricultural land. The trouble is that some of this land is currently covered by tropical rainforests. When farmers cut down rainforests for farms and ranches, the dead trees release carbon dioxide and other greenhouse gases into the atmosphere (just like when fossil fuels are burned). Further the destruction of rainforests displaces indigenous people and kills wildlife. Therefore biofuels are having a significant impact on the environment.

Some biofuels are less bad than others. When crops are grown on abandoned agriculture lands and in areas that are not covered by natural ecosystems, they can have a low impact on the environment provided that fertilizers and pesticides are not over-used. In the future, new types of biofuels will produce even less greenhouse gas emissions and may actually help the environment. For example, the use of native grasses for biofuel production in the United States could offer higher biofuel yields and generate less pollution than corn-based ethanol. At the same time, these grasses can enhance soil fertility and do not drain the water table.

More articles on biofuels

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