How Much Matter Died to Fill Your Tank?

Nov. 6 -- Jeff Dukes was driving his lab's huge SUV through the red hills of southern Utah when he asked his wife a question that seemed simple at the time, but led to an astonishing answer.

"We're burning a lot of gas," noted Dukes, then a postdoctoral researcher in ecology at the University of Utah. "Where does all that gas come from?" he asked his wife, also an ecologist.

Months later, after extensive research, Dukes has found his answer. And it casts a new light on the precarious hole that modern humans have dug for themselves.

It turns out that it took tons and tons of tiny plants and animals, buried at the bottom of the seas, lakes or river deltas, to produce every gallon of gasoline that poured through the big engine of that SUV.

It took 98 tons, to be exact, or 196,000 pounds. For every gallon.

Lot of Dead Matter

"That's a shocking number," says Dukes, who is now en route to a new post at the University of Massachusetts in Boston.

And of course nobody burns just one gallon of gasoline. That probably barely got the engine started in Dukes' SUV. We burn millions of gallons every day, and we rely on fossil fuel for a wide range of other energy needs. So how much prehistoric plant and animal material do we need to get through a single year?

Dukes zeroed in on the year 1997, and relying on reports from various agencies, including the United Nations, he came up with statistics that are really astonishing.

He found that the total amount of fossil fuel burned that year amounted to 97 million billion pounds of carbon. That's equivalent to more than 400 times the plant material produced by the entire world during a single year.