Photo credit: Flickr/Keoni Cabral.

Last August, a guy ordered one of the most expensive fast-food burgers in the world at a Jack in the Box (JACK 1.06%). The 20-patty burger, which also included several strips of bacon and cheese, stood about 12.5 inches tall and was an estimated 9,044 calories. The price tag on that monstrosity was $38.23. While that was the monetary cost of the burger, it wasn't its true cost.

The carbon cost of beef
Beef production takes its toll on the environment. According to the Meat Eater's Guide to Climate Change + Health, beef has the second largest carbon footprint of the 20 most common foods it compares. Only lamb has a worse carbon footprint.

The reason cows and sheep score so poorly is due to their digestive process, called entric fermentation. The process creates a substantial amount of methane, which is 25 times more potent than carbon dioxide. On top of that, the nitrous oxide these animals leave behind has the warming potential that's 300 times greater than carbon dioxide.

Consequently, 90% of beef's emissions are created when it's in the production phase, or when the cow is simply growing up. Chicken, on the other hand, produces half of the emissions of beef during the production phase because chickens don't produce any methane. Not only that, but chickens require much less feed per pound of protein, which lowers emissions from feed production as well.

The Meat Eater's Guide puts these 20 foods into the carbon footprint equivalent of driving a car. Its findings suggest that consuming 4 ounces of beef is the carbon equivalent of driving just over 6.5 miles. Chicken, on the other hand, has the carbon equivalent of driving just over 3.5 miles.

Photo credit: Jack in the Box.

Adding up that Jack in the Box burger
The adventurous burger builder based his $38.23 creation on a Jumbo Jack burger. To find the carbon footprint of that burger, we need to know how much beef it contains. The tricky part is that Jack in the Box actually never says how much beef is in its Jumbo Jack burger, and a call into its guest-relations department came up dry. However, in comparing similar burgers, the general consensus is that the Jumbo Jack burger is about a quarter-pound, or roughly four ounces of beef before it's cooked. That puts it a bit bigger than the 3.2 ounces of beef found in a Big Mac, though roughly in line with a quarter-pound burger. Add up the 20 patties on the Jack in the Box monster burger and we have roughly 80 ounces, or about 5 pounds of beef.

Again, using the Meat Eater's Guide, every 4 ounces of beef is the carbon footprint equivalent of driving 6.5 miles. That puts the estimated carbon footprint of this mammoth Jack in the Box Burger the same as driving 130 miles in a car.

Food for thought
Driving a car more than 130 miles is actually what I'd have to do in order to reach my nearest Jack in the Box. So the burger buyer doesn't need to worry, as I've already offset his carbon footprint. However, by knowing more about the carbon footprint of the foods we eat, as well as the nutritional value, it can steer us toward making better overall choices. While I'm never one to turn down a good burger, knowing that chicken is the better meat is something that can help me make the tough choice between two dishes if it's a toss-up.