A whopping 58 percent of the Spud State's energy-related emissions in 2010 (the most recent year tracked) came solely from transportation, narrowly beating out California, New Jersey and Oregon in that department. On the other end of the spectrum, just 13 percent of North Dakota's energy-related emissions came from transportation, while Indiana checked in at 19 percent. Click here (PDF) for the 21-page EIA report.
Naturally (or not so naturally, in this case), California in 2010 had both the largest amount of transportation-related emissions (Texas was a close second) and most total energy-related emissions, belching 370 million metric tons of CO2 into the golden sky. Optimists will point out that that figure is down 11 percent from a decade earlier. So we have that going for us.