Carbon Emissions in Washington, D.C.—Is It Really the Lowest in the Country?

I ran across one statistic the other day that said that Washington, D.C. was the lowest carbon emitting state or district in the nation. Bold claim?

As of 2013 (the most recent full data set), the average resident of the District of Columbia emitted 5.12 tons of CO. At less than a third of the national average (17.46 tons), this is the lowest carbon dioxide emissions of any state or district in the Union.

So—how is that possible? There are plenty of jurisdictions (i.e. Vermont and California) that take environmental protection and climate change much more seriously.

The short answer is that dense urban areas have low carbon footprints. Because the District has no exurbia and no far-flung hinterland within its technical range, it’s almost cheating.

The Rankings

Considering that lack of size, the order of highest to lowest COemitters is not all that surprising (and yes, it’s from Wikipedia, but I’ve checked the sources, so don’t worry, you nit-picks—you know who you are). And there, alllllllll the way at the bottom is little old Washington, D.C.

Rank Jurisdiction Annual CO2 emissions CO2 emissions
(in millions of metric tons) per capita
(in metric tons)
1 Wyoming 64 112.8
2 North Dakota 54 73.51
3 Alaska 38 52.71
4 West Virginia 96 51.75
5 Louisiana 223 48.75
6 Kentucky 148 33.89
7 Montana 32 31.98
8 Indiana 207 31.77
9 Iowa 84 28.53
10 Nebraska 52 28.37
11 Oklahoma 107 28.28
12 New Mexico 57 27.23
13 Alabama 129 26.85
14 Texas 656 25.59
15 Kansas 73 25.21
16 Arkansas 67 22.8
17 Utah 64 22.74
18 Missouri 133 22.56
19 Mississippi 60 20.56
20 Ohio 233 20.19
21 Pennsylvania 245 19.22
22 Colorado 91 17.98
23 South Dakota 14 17.92
24 Illinois 225 17.5
25 South Carolina 78 17.16
26 Minnesota 91 17.02
27 Wisconsin 96 16.81
28 Tennessee 103 16.09
29 Michigan 157 15.9
30 Georgia 154 15.69
31 Delaware 12 14.44
32 Arizona 92 14.23
33 Hawaii 19 14.01
34 Maine 18 13.27
35 North Carolina 123 12.74
36 New Hampshire 16 12.46
37 New Jersey 110 12.45
38 Nevada 33 12.44
39 Virginia 97 11.97
40 Florida 227 11.9
41 Maryland 64 10.96
42 Rhode Island 11 10.51
43 Washington 69 10.38
44 Idaho 16 10.12
45 Massachusetts 66 9.99
46 Connecticut 33 9.84
47 Oregon 36 9.63
48 Vermont 6 9.42
49 California 364 9.18
50 New York 158 8.1
51 District of Columbia 3 5.12

The winner is Wyoming, which is cold and has a disparate population, which work to boost energy use and emissions. The runner up should also be no surprise—after all, Texas is massive territory and home to the self-proclaimed Energy Capital of the World, Houston.

The bottom five emitters per capita starts with Oregon, California and Vermont, no surprises there. New York, which in the energy sphere has been able to do things even California wishes it could do, takes the number two spot. And then there, all the way at the bottom is Washington, D.C.—a complete outlier at 37% fewer emissions than New York.

What We’re Measuring

CO2 emissions can be measured in pounds, tons, or metric tons, depending on which carbon footprint measurement website you use and country you’re in. I’ve chosen to break it all down to good old fashion American short tons of 2240 lbs each. That’s what the EPA uses, so it’s good enough for me.

According to a little division (EPA total COemissions over Census Bureau data), the average American individual emits 17.46 tons of carbon dioxide per year. However, that doesn’t include the total GHG emissions measured by COequivalent—tons of each GHG multiplied by their respective “greenhouse gas effect.”

Other anthropogenic greenhouse gases (GHG)—methane, nitrous oxide, ozone, chlorofluorocarbons—are usually measured in terms of CO2 emissions equivalents, as well, and are sometimes rolled in, inflating the number. Once added in, that raises total average emissions per capita to 21.17 tons.

Which of these numbers you come up with (17.46 tons or 21.17 tons) also depends on who’s dishing the info. But in either case, the Washington, D.C. still has the lowest levels of any federal state or district in the country. The rankings Wikipedia shows are strictly in COemissions, and considering the trickiness of measuring other GHGs, I think it’s better to stick to simple CO.

The Caveat

The biggest asterisk to the right of this measurement is indeed that Washington, D.C. is obviously a pure urban area. Because of public transportation, the propensity of urban citizens to walk, and the economies of scale for programs such as recycling and bike shares, urban areas produce lower CO2 emissions than rural areas.

The oddest part of that caveat is that cities—American cities anyway—are immediately surrounded by a massive ring of the highest polluting neighborhoods. This can probably be attributed to a combination of economic prosperity and driving into or otherwise economically engaging with the nearby city. It’s like this across the East Coast (and the nation):

 

EastCoastMSAs-750

Thanks to University of California, Berkeley’s CoolClimate Maps

So while Washington DC does have the lowest when put on the scale with other states—it simply doesn’t have the same carbon emission diversity as a full size state. Even Rhode Island makes the top of the list for reasons that I can imagine have more to do with size and density than policy.

The “Real” Rankings

When we look at how the Maryland, DC, Northern Virginia (MDV) area stacks up, it doesn’t really rank all that high. Unlike most urban areas other than New York, the metropolitan area is made up of three distinct state jurisdictions, which makes coordination complicated.

By another study’s measurement, the DC metropolitan area is #10 out of the 20 largest metropolitan areas for emissions per capita—ranked by residuals from the author’s econometric model. However, another study said that there may not be economies to scale of large cities. At just over 6 million, the MDV area is ranked the sixth largest metropolitan statistical area. Therefore (according to this study), when we control for size, we may not really be that far down the rankings.

The only study that does seem to measure COlevels by metropolitan statistical areas without any models also ranked DC nearer to the middle. The MDV area was #27 of 66 (from lowest to highest polluting) metro areas in their list. The abstract says that cities in California generally had the lowest emissions profiles and cities in Texas and Oklahoma were the worst performers.

So, once all those things are factored in, looks like DC is right in the middle. While it’s the lowest emitting of the 50 states and the district, it’s ranked in the top third of highest emitting metro statistical areas. Per usual, the truth is somewhere in between—we’re no poster child, but we’re not as bad as Texas.

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