A number-filled report released yesterday by the National Academy of Sciences suggests that our current fossil fuel-based transportation economy isn’t as cheap as we think it to be — yet it’s just as crude. (Ha!)

According to The New York Times‘ summary of this report, the United States loses approximately $120 billion every year due to health costs associated with the burning of coal, gas, oil and even hippiefied ethanol:

“The largest portion of this is excess mortality — increased human deaths as a result of criteria air pollutants emitted by power plants and vehicles,” said Jared L. Cohon, president of Carnegie Mellon University in Pittsburgh, who led the study committee.

Nearly 20,000 people die prematurely each year from such causes, according to the study’s authors, who valued each life at $6 million based on the dollar in 2000. Those pollutants include small soot particles, which cause lung damage; nitrogen oxides, which contribute to smog; and sulfur dioxide, which causes acid rain.

The study lends support to arguments that society should pay extra for energy from sources like the wind and the sun, because their indirect costs are extremely small. But it also found that renewable motor fuel, in the form of ethanol from corn, was slightly worse than gasoline in its environmental impact.