According to the EPA, a total of 14.33 billion RINs were generated last year, translating to a production of 14.33 billion gallons of ethanol.

The latest ethanol export data from the Energy Information Administration (EIA) shows exports totaling 680.8 million gallons. If we were to annualize that figure, exports in 2014 would total 817.03 million.

As such, domestic ethanol consumption last year would have been 13.52 billion gallons representing 9.87 percent of the nation's motor fuel usage (total motor gasoline usage in 2014 was 136.92 billion gallons). By using the EIA's formula for calculating CO2 emissions, ethanol use last year prevented the release of 42.8 million metric tons of CO2 into the air. 

That, according to the EPA's greenhouse gas equivalencies calculator, is the same as removing 9.01 million cars from the road for a year. It is also the same as removing 11.2 coal-fired power plants for a year. And lastly, it would take 11,782 wind turbines to achieve the same result as ethanol.

Had the nation's fuel supply comprised of 15 percent ethanol in 2014, we would have prevented 65.31 million metric tons of CO2. And this would have been the equivalent of removing 13.75 million cars from the road for one year (interestingly enough, in 2014, there were 16.5 million new cars sold).