I'll take a pound of CO2 with that cheeseburger...

Somewhere along the line you've probably heard it too. It goes something like this...for every umpteen miles we drive our car, x pounds of carbon are released into the atmosphere. "What?", you say. "Pounds of carbon? Not dropping out of my tailpipe, but rising up into the atmosphere?"

To think about it, it doesn't really make much sense, does it? How can all those tons of carbon stay up there? And how can the stuff that comes out of my tailpipe, which I think of as being a 'gas' (vs. gasoline), actually weigh that much? Which brings me to one notion behind this post. You see, for all the information we're getting nowadays on greenhouse gases--and how they're created, what they're doing up there, and how they can be reduced both on the front and back end of things (through reabsorption by trees, the oceans, etc.)--I worry that it's the little things that can trip us up on the road to eConsciousness. Things like just not getting the concept of--well, how carbon can 'float'.

So before we turn to dietary issues, let's take a minute to defuse this potential stumbling block. It's not even that complicated. The principle is captured in the diagram above (and in the larger, more detailed version you'll see by clicking on the visual below). Numbers aside for the moment, what essentially happens is:

Combustion breaks apart the components of gasoline, namely hydrogen and carbon, and recombines them--the carbon, that is--with oxygen. "So..." Well, here's the important part. Each component has a molecular weight: hydrogen being 1, carbon being 12, and oxygen being 16. So, when the carbon from your gas tank combines with oxygen from the air, you're actually manufacturing CO2--one carbon and two oxygens together, and about three times as heavy as carbon component in the original gasoline.

And off they go. Pounds and pounds of CO2 molecules. Tons and tons as time goes on...at a rate of almost 20 pounds for each gallon of gas you burn. I'll repeat: 20 pounds of the stuff for every gallon you burn! No matter how efficient a car you're driving. Whether for business, for fun, or--heaven forbid--just idling.

So I thank carbon offets guru, Adam Stein of TerraPass, for crunching all the numbers and explaining the science (on his TerraBlog post). Plus visual modeler extraordinaire, Marshall Clemens of Idiagram for helping create the marvelous diagrams shown here. With their help, maybe the point will reach more of you, more effectively. Think about it.

Now, for what a cheeseburger can teach us about CO2...

Fortunately, while we're all trying to get a handle on the basics, we've got folks like Jamais Cascio, who on his Open the Future blog shares insights from his research. And the news isn't great. Intrigued by the question of what the carbon footprint of another typical American staple, the cheeseburger, might be, he came up with some startling factoids. Consider this...

- The average American eats about 150 burgers a year.

- Between a quarter- and a half-kilogram of carbon dioxide are emitted in the production and consumption of one cheeseburger (calculating everything from raising the cattle and making the buns, to the transportation that gets the burger--and us--to the burger joint).

- Over the course of a year, according to Jamais, between 37 and 75 kilograms of carbon emissions result from the average American's cheeseburger habit.

And there's more...like the methane gas that the cattle generate (with about 20x the greenhouse gas effects of CO2), and so on. (You can hear much of this discussed in a fascinating interview with Jamais on TreeHugger Radio). But the message is clear. What we eat, and all the energy required to make it, transport it, and enjoy it contributes significantly to greenhouse gases (GHGs). No wonder it's fueling a skyrocketing interest in growing, buying, and consuming locally. That, though, is a topic for another post, so stay tuned.

By the way, Jamais refers in his piece to a report from Stockholm Unversity and the Swiss Federal Institute of Technology, titled Energy Use in the Food Sector. For those of you interested in some of the fascinating details, check out the PDF here.

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Comments

[John Lawrence]

Very interesting. Who would have thought that more CO2 by weight is created than the weight of the original gasoline? I've never heard this explained so succinctly till I read your blog.

[Jim Sage]

As I learned physics 50 plus years ago, a gas has no weight, only solids and liquids.