The Green Machine prefers propane for environmental, convenience, and food safety reasons. Even if the charcoal is made from waste wood that in turn came from trees that sequestered carbon, my point is it is better to leave the trees standing or rotting returning nutrients to the earth rather than convert them into charcoal In addition to soot there are dozens of chemicals in charcoal smoke that are carcinogenic. Propane is a simple hydrocarbon with the chemical formula C3H8. Combusting propane yields only carbon dioxide and water. Fat that drips onto the ceramic or steel burner plate in a propane fired BBQ also forms carcinogens. However if one uses burners that are aside of where the meat is cooking and indirect heat is used then the source of carcinogens is avoided. It is much more difficult to push the coals from side to side in the BBQ grill on avoid these carcinogens infiltrating your meal.
This discussion on charcoal has made me remember some research I did in 2003 for a book I published in Japanese on Sustainability. I discovered then that much of the forest in Somalia was being cut down to produce charcoal for export. I thought that these exports of charcoal would be to Europe or other neighboring African States. Sadly the export of the Somali charcoal was to Saudi Arabia where charcoal is called Black Gold and sells for more than $10 a bag. From a sustainability view point this is crazy. Saudi Arabia has more fossil fuel than anywhere else in the world and the Saudis should use their propane for BBQs and camp fires rather than charcoal.
Several US chemical companies plan to produce hydrogen, methanol, and ammonia by gasifying petroleum coke. I have the suggestion for these big chemical companies to package the coke in bags and sell this packaged coke to the Saudis. We could give the Somalis a portion of the revenues from the sale of the petroleum coke and save their acacia forests. This would be a win-win proposition for all and finally the US could export something back to the Saudis. I need to go back to the BBQ to tend to my meal because I know that independent of whether we BBQ with briquettes or with Propane the entire US population's total Carbon Dioxide emissions from our BBQs is less than 0.15 million tons a year or about 0.002% of our collective 6.6 billion tons of carbon dioxide emissions in the USA last year. Remembering that chicken is greener than beef, I will put another chicken breast on the grill. If I was Australian I may put another shrimp on the BarB.