 The GHG emissions are then compared to the life cycle emissions of 2005 petroleum baseline fuels (base year established as 2005 by EISA) displaced by the renewable fuel, such as gasoline or diesel.The life cycle GHG emissions performance reduction thresholds as established by EISA range from 20 to 60 percent reduction depending on the renewable fuel category.The demand for ethanol fuel in the United States was stimulated by the discovery in the late 1990s that methyl tertiary butyl ether (MTBE), an oxygenate additive in gasoline, was contaminating groundwater.