Tucson Region

Tucson 17th-lowest in carbon emissions

By Tony Davis

Arizona Daily Star

Tucson, Arizona | Published: 05.29.2008

Tucson's carbon footprint is among the lowest compared to most of the country's major metro areas. But it's getting worse, says a new study from a Washington, D.C.-based think tank.

Tucson ranked 17th-lowest out of the 100 largest metro areas in the level of per-person carbon emissions from household energy use and vehicle traffic in the Brookings Institution study covering the period 2000 to 2005.

But metropolitan Tucson's per-person production of CO2 — the most common greenhouse gas linked to global warming — has been steadily rising since 2000 at rates far exceeding the average for those 100 metro areas and the national average.

"While Tucson is doing well, it cannot get complacent, especially on carbon emissions from automobiles," said Andrea Sarcynski, a Brookings senior research analyst.

Nationally, the study found that large metro areas generally did better on per-capita carbon footprint than the national average, and that higher-density cities with rail transit systems generally did better than lower-density, sprawling cities relying mainly on automobiles.

Lower-density, car-dependent Tucson was an exception, as was sprawling Phoenix, which ranked 21st lowest in the overall Brookings survey.

Why Tucson does well

● We're low-carbon emitters at home, partly because it's warm here and Tucsonans don't need to use nearly as much heat as major Northern and Eastern cities.

In 2005, the average Tucsonan emitted 0.606 of a ton of carbon from home energy use, ranked 16th nationally, compared to 1.16 tons from the average American and 0.925 of a ton from the average resident in the top 100 metro areas.

● We're lucky. The study's good ranking for Tucson's carbon generation from electricity usage was based partly on the fact that the researchers lumped Tucson in with the entire state for carbon generated per megawatt hour of electricity used.

Arizona as a whole does well on that score because Phoenix gets a lot of nuclear and hydro-electric energy, which aren't nearly as carbon-intensive as coal-fired power plants.

But Tucson Electric Power's energy supply is 78 percent coal, which puts us up there with coal-reliant Kentucky and West Virginia.

Tucson should be concerned

● As for the transportation-based carbon footprint for the average Tucson motorist, Tucson ranked 46th out of 100 metro areas. The carbon footprint used by drivers of trucks in Tucson fared particularly poorly, ranking 74th out of 100 metro areas.

● The transportation portion of our carbon footprint rose 7.8 percent from 2000 to 2005, compared to 2.4 percent in all the top 100 metro areas.

Metro Tucson's overall carbon footprint, considering home energy use and transportation, rose 5.97 percent in that period, compared to a 1.1 percent increase for the top 100 metro areas.

'Carbon footprint' defined

A measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide.

Your carbon footprint is the direct effect your actions and lifestyle have on the environment in terms of carbon dioxide emissions.

It measures the gases given off when carbon changes form — when coal is burned to generate electricity or gasoline is consumed to power your car.

footprint rank

The metropolitan areas with the smallest and largest per-capita carbon footprint in 2005, according to a study by the Brookings Institution. Metropolitan areas may cover more than one state.

Smallest:

1. Honolulu.

2. Los Angeles-Long Beach-

Santa Ana, Calif.

3. Portland-Vancouver-Beaverton (Oregon-Washington).

4. New York-Northern New Jersey-Long Island.

5. Boise City-Nampa, Idaho.

6. Seattle-Tacoma-Bellevue, Wash.

7. San Jose-Sunnyvale- Santa Clara, Calif.

8. San Francisco-Oakland- Fremont, Calif.

9. El Paso, Texas.

10. San Diego-Carlsbad- San Marcos, Calif.