Environmental News Service
Gasoline Costs 98 Tons of Plants per Gallon

SALT LAKE CITY, Utah, October 27, 2003 (ENS) - Ninety eight tons - 196,000 pounds - of prehistoric buried plant material is required to produce each gallon of gasoline, according to a new study.

It finds that the total amount of fossil fuel burned in 1997 totaled 97 million billion pounds of carbon; a figure that is equivalent to more than 400 times all the plant matter that grows in the world in a year, including microscopic plant life in the world's oceans.

"Every day, people are using the fossil fuel equivalent of all the plant matter that grows on land and in the oceans over the course of a whole year," says study author Jeff Dukes, an ecologist at the University of Utah.

The study, titled "Burning Buried Sunshine: Human Consumption of Ancient Solar Energy," will be published in the November issue of the journal "Climatic Change."

Fossil fuels developed from ancient deposits of organic material and can be thought of as a vast store of solar energy that was converted into plant matter by photosynthesis, Dukes explained.

Using published biological, geochemical and industrial data, he estimated the amount of photosynthetically fixed and stored by ancient plants carbon that was required to form the coal, oil and gas that we are burning today.

The ecologist calculated that 4.87 kilograms of oil are needed to make a gallon of gasoline. Oil is 85 percent carbon, Dukes says, therefore 4.14 kilograms of carbon are needed to make enough oil to produce one gallon of gasoline.

He explains that because a very low percentage of the original carbon in ancient plant material actually ends up as oil, it takes some 98 tons - 89 metric tons - to produce one gallon of gasoline.

"It took an incredible amount of plant matter to generate the fossil fuels we are using today," says Dukes. "The new contribution of this research is to enable us to picture just how inefficient and unsustainable fossil fuels are - inefficient in terms of the conversion of the original solar energy to fossil fuels."