October 24th, 2006

Lexi in the woods

confused by CO2 math

According to an article in today's Slate on getting around while burning less CO2, "For each gallon of gas your car burns, it releases about 19 pounds of carbon dioxide."

According to the Santa Cruz Public Libraries Ready Reference File page Weight of One Gallon (U.S.) of Water, Gasoline, and Ethanol, "1 gallon of gasoline equals 5.8 to 6.5 lbs."

I don't understand this — how can burning roughly six pounds of gas produce three times that weight in carbon dioxide? How does this not count as creating something from nothing (which sounds much like a perpetual-motion machine to me)?

If anyone can explain this or point me to a source that explains it, I'd be most appreciative.