Propane or Charcoal?

Gertner wrote in the green edition of New York Times magazine:

Barbecuing, as any guy grilling a flank steak will tell you, is as much about process as product. Propane gas versus charcoal is typicaly a debate about flavor, not carbon-dioxide emissions. But let's ask anyway. Which is greener? Probably charcoal, according to Tris West, an environmental scientist at Oak Ridge National Laboratories, who last year calculated emissions from the two methods.

He says that since charcoal is derived from wood - and thus trees that took in atmospheric carbon as they grew - burning it on the grill is pretty close to a “net zero” in terms of carbon emissions. Propane, by comparison, is a fossil fuel that adds to greenhouse-gas accumulations. West cautions, though, that it gets a little more complicated than that. Even if burning charcoal is technically greener, it may release particulates into the atmosphere. (Food scientists also warn that it can be less healthful.) It's good to know that your choice won't effect any significant change in mass carbon emissions. By West's estimation, the total amount of carbon dioxide released from barbecue grills on July 4 is on the order of .003 percent of the annual U.S. total.