Research into biofuels began in earnest soon after the oil crisis of 1973. By the early to mid-1990s, biofuels emerged as a serious alternative to fossil fuels, and were touted as an Earth-friendly answer to the need for lower fossil fuel carbon emissions and a reduction of foreign dependency on overseas oil. In essence, biofuel is an energy resource that is derived either from living organisms (called biomass) or from waste biomass (also called biowaste). It can be produced in solid, liquid, and gaseous form, but since it is used mostly for transportation, it is primarily found in liquid form.

In the public debate, biofuels generally refer to ethanol or biodiesel, the former favored by the Americas (Brazil and the United States produce 90 percent of ...