Although production of ethanol tripled from 2002 to 2009, not everyone supports the process [source: NCGA]. Some critics worry that ethanol production could result in shortened grain supplies and lead to malnutrition around the world, which seemingly undermines the benefits of producing the alternative fuel. The National Corn Growers Association says, however, that there is plenty of corn for food and fuel to go around [source: NCGA]. But critics' concerns over ethanol production do not end here -- some say there's potential for skyrocketing prices and negative effects on the environment. It's possible that drought or some other natural event could affect corn crops, which in turn would affect ethanol prices. Of course, corn is not the only agricultural product that can go into ethanol; waste products can be used to make the biofuel. And when ethanol is produced from corn, only the starch goes into the fuel, leaving other viable corn products to pass on to consumers -- among both the human and livestock worlds. But how green is all this?

Even though producers seem to make efficient use of the products and byproducts for manufacturing ethanol, its production still adds to greenhouse emissions: Manufacturers of ethanol have to burn some fossil fuels when they make the product. However, proponents of ethanol production would answer that concern saying that it's possible that cellulosic ethanol -- made from plant stalks and stems -- can be produced more cleanly.

Obviously, there are many sides and issues surrounding the production of ethanol. Keep reading to learn more about the controversies and how it might affect global nutrition and the environment. And find out if it's even possible to make your own ethanol.

Ethanol production -- how efficient is it, really? Image Credit: ©iStockphoto.com/photosbyjim

Does ethanol have to be produced from corn?

Although most ethanol is produced from corn, scientists can produce ethanol from agricultural materials such as citrus, algae, switchgrass, corn cobs and corn stover (the leaves and stalks left in the field after corn is harvested). Scientists can also make ethanol from the following waste products: paper pulp, wheat straw and rice straw.

How would a severe drought influence the price of ethanol?

Ethanol is usually produced from corn. Therefore, it would follow that if a severe drought affected the corn crop, ethanol prices would rise. However, the amount that ethanol prices would rise is hard to imagine. Historically corn has been grown for food, not fuel. If a severe drought were to affect the corn crop, ethanol producers would be competing with food suppliers for the little corn that was harvested. This would drive corn prices very high, very quickly. Iowa State University researchers published a study stating that a severe drought would make corn so expensive, ethanol production facilities would be forced to shut down [source: McPhail and Babcock].

Does ethanol production contribute to starvation worldwide?

Ethanol production's effect on hunger worldwide is hotly debated.

• Some feel ethanol production not only contributes to existing hunger worldwide, it causes more starvation globally. These activists feel that diverting corn crops to ethanol production causes malnourishment around the world. Jean Ziegler, the U.N. Special Rapporteur for the Right to Food called biofuel production, referred to it as a crime against humanity [source: Cendrowicz].
• Others contend there is enough food to feed the world's hungry, but the problem is delivering food to those in need. Often food can't be transported because there are no roads, or the political situation is unstable [source: National Corn Growers Association].

Is ethanol production subsidized?

The United States government subsidizes ethanol production, as well as the production of all other biofuels, in the form of tax breaks. Companies that produce biofuels lobbied the U.S. government for tax breaks, arguing that if they didn't receive some sort of government assistance, they wouldn't be able to compete with fossil fuel producers (who do receive federal assistance). The government responded by passing the Energy Act of 2005, which offers a 51-cent per gallon tax credit to companies producing ethanol.

Can you make your own ethanol?

It is relatively easy to make your own ethanol, since the process simply involves fermenting and then distilling a feedstock, such as corn grain. But because ethanol is alcohol, its production is carefully regulated and requires a permit. If you want to use corn as your feedstock, just remember that it takes about one acre (0.4 hectares) of corn to produce about 330 gallons (1,250 liters) of ethanol.

How green is ethanol?

One of the things people criticize about ethanol is its small effect on greenhouse emissions. Since fossil fuel is burned when processing corn ethanol, the total amount of greenhouse emissions produced is almost the same as that produced by fossil fuel alone. In fact, corn ethanol only reduces greenhouse emissions by about 20 to 30 percent. However, according to the Energy Information Administration, cellulosic ethanol has twice the energy potential of corn ethanol, and it reduces greenhouse emissions by about 80 percent.