Since the earth has a finite supply of fossil fuels and they are not being replenished (or are being replenished at a rate that is of no use to us) it is just a matter of time before we run out of gas. Literally. In the US, one proposed alternative is corn ethanol.
The basic idea is that corn is converted, via fermentation, into ethanol. This process is similar to that used to create moonshine, so we Americans have this down quite well. Using corn for fuel has several advantages. First, we can grow the corn in the US and hence it can help reduce our dependence on outside sources of fuel-especially sources in the Middle East. Not having to rely on that part of the world would be a good thing. On the downside, the economies of the countries there largely depend on oil and, looking into the distant future, an economic collapse combined with radical Islam could lead to a nightmare of epic proportions. Second, corn is renewable-we can plant more every year. Third, corn ethanol produces 22% less green house gas emissions than gasoline (according to the US Department of Energy, as cited on page 44 of the October, 2007 issue of National Geographic).
As with all things, there are some downsides to corn ethanol. First, there is some indication that the process of converting corn into ethanol actually uses more energy than it produces. Producing fuel at a loss is obviously not a good idea. Second, ethanol is currently more expensive than gasoline in terms of the energy it provides. Of course, as gas gets more expensive, this can change. Third, corn is a food crop. This means that corn made into fuel is not available for food and that the price of food based on corn will increase (due to the competition from those buying it for fuel).
Corn is, of course, not the only possible source of biofuel. Sugarcane, for example, is an extremely appealing source. Sugarcane conversion is very effective-for each “unit” of fossil fuel used one gets eight “units” of sugarcane ethanol. It also produces 56% less greenhouse gas than gasoline.
The US is focusing on the inferior corn ethanol-mostly because of the power of the relevant lobbies. Perhaps some day we will end up having “big corn” replace “big oil.”