Biofuels used under the US’ expanded Renewable Fuel Standard (RFS2) have reduced greenhouse gas emissions by 354 million tonnes between 2008 and 2015, according to a study, unveiled Friday by the US Renewable Fuels Association (RFA).
The association said that the RFS had in fact exceeded expectations in terms of emissions reduction due in part to technology improvements in grain ethanol production. According to the report, conventional corn ethanol cut emissions by an average of 29% in comparison to the petroleum actually used in 2008, with that cut going up to 39% by 2015.  Ethanol is the major component of the RFS2. The study puts the country’s current corn ethanol production capacity at 14.4 billion gallons.
The RFS programme, created in 2005 and expanded in 2007, requires increasing amounts of renewable fuel to be blended into transportation fuel, reaching 36 billion gallons by 2022.
The study comes as the US Environmental Protection Agency (EPA) is due to announce its final renewable fuel quotas for the years 2014, 2015 and 2016 by November 30. Its initial proposals in May called for the use of 16.3 billion gallons of renewable fuels this year, including roughly 13.4 billion gallons corn ethanol, and 17.4 billion gallons of biofuels for 2016, including around 14 billion gallons corn ethanol.  The RFA said the study had important implications for the final rule for 2014–2016 RFS volumes as well as the upcoming global climate summit in Paris.