My Car’s Carbon Emissions are How Big?!?!?

April 17, 2012 | 9:43 am
David Friedman
Former contributor

So, you want to cut your carbon emissions and maybe even save some money? Well, start with what you drive and how you drive it. When it comes to the largest contribution you make to climate change, the culprits are most likely parked in your driveway. That’s one of the key findings in a new book, Cooler Smarter: Practical Steps for Low-Carbon Living, that I helped write with a team of researchers at UCS.

Cooler Smarter: Practical Steps for Low-Carbon LivingThis is part of a series on Cooler Smarter: Practical Steps for Low-Carbon Living.

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The book’s lead author guest blogged about the 21 tons of greenhouse gas emissions the average American is responsible for emitting each year. And if you look at this figure in his blog, you will see that personal transportation stands out at 28 percent of that total, more than any other category. As you will see below, the biggest-by-far portion of that comes from our daily driving.

Auto Emissions: The Pac-Man Principle

To understand why our daily driving is such a big part of our personal carbon emissions, you just have to look at a few numbers. (Geek alert, my love affair with numbers continues.)

  • There are about 240 million cars and light trucks on U.S. roads—that’s one for every person who has a license.
  • Those vehicles are driven 2.7 TRILLION miles a year—enough to make more than 14,000 round-trip voyages to the sun.
  • The average auto gets just over 20 miles to the gallon (mpg) at 25.7 pounds of heat-trapping emissions to produce, deliver, and burn a gallon of gas.

    David’s 80’s-video-game-inspired Pac-Man Principle: American’s average car and light truck emissions effectively gobble up all other forms of personal transportation.

  • Combined, that is 3.3 trillion pounds, or nearly 1.7 billion tons of heat-trapping emissions!

Our autos are responsible for more carbon dioxide emissions than the entire economies of all but four nations in the world.** In comparison, the next largest personal transportation source is air travel. But at only 0.37 trillion miles a year for vacations and visiting friends and relatives, personal air travel just can’t compete with daily driving.

Where do all these numbers lead us? Well, if you take a look at the pie chart to the right, and if you played a lot of video games in the 80s as I did, it leads to the Pac-Man Principle: Americans’ average transportation emissions are dominated by our cars and light trucks, which effectively swallow up all other forms of personal transportation.

Get on the Road to Your 20 Percent Carbon Reduction Today

Some of you may be stunned by our guzzling ways. Others might find this all too obvious. So, now what?

Well, no matter which camp you fall into, the next time you buy a vehicle, boost your mpg. If you are not in the market this year, don’t worry, your time will come—most Americans switch autos about once every five years. Meanwhile, tune up your car, pump up your tires, and avoid aggressive driving and you could save more than $500 on gas in a year. Carpool, take the train, or bike to work once a week and you can save more than $200 a year. And together, just these steps can cut your total annual carbon emissions 5-10 percent.

If you want to learn more about what you can do to cut your personal transportation emissions, or what else can deliver a big bang for your buck when it comes to meeting our 20 percent challenge, check out the book. And if you are waiting for it to arrive in the mail, start right away with our website that shows you 20 personalized ways to start cutting your carbon footprint by 20 percent over the next 20 days.

**NOTE: International emissions data can be found here, but that data is in metric tons of carbon, so you have to convert the 1.7 billion tons of carbon dioxide for our cars and light trucks into metric tons of carbon. To do so, multiply by both the conversion factor of 0.907 metric tons per ton and the atomic mass of carbon (12) and then divide by the atomic mass of CO2 (44) . You should get about 0.412 billion tons of carbon (412,000 thousand metric tons of carbon).