Nowhere in Arizona do the residents emit more carbon dioxide than in Ahwatukee and Paradise Valley.
University of California-Berkeley researchers measured the carbon footprint of the average household in nearly every ZIP Code in the United States and put all that information on a map.
"The primary drivers of carbon footprints are household income, vehicle ownership, and home size, all of which are considerably higher in suburbs," the researchers say. "Other important factors include population density, the carbon intensity of electricity production, energy prices, and weather. The model includes 37 local variables in total."
That takes out the mystery as to why households in Ahwatukee and Paradise Valley would have the largest carbon footprints. (Though the study includes all of Paradise Valley, only one Ahwatukee ZIP Code made the bad list -- 85045, which includes the Club West and Foothills Reserve neighborhoods.)
In those ZIP Codes, the percentage of households pulling in more than $100,000 is between 55 percent and 57 percent, which is more than Beverly Hills' famed 90210 ZIP Code. As more money comes in, there's generally more consumption.
Consider that it takes more energy to keep a $10 million Paradise Valley estate at 69 degrees than it does a 1,000-square-foot ranch home in Maryvale.
According to the UC-Berkeley study, the average household in Ahwatukee's 85045 ZIP Code is producing 74 metric tons of carbon dioxide per year, and nearly 73 tons in PV.
Meanwhile, the average household's emissions are substantially lower everywhere around Central Phoenix. In the 85014 ZIP Code -- roughly between Thomas Road and Glendale Avenue and Seventh and 16th streets -- the average carbon footprint is half of PV's or Ahwatukee's offending ZIP Codes.
The main finding of the study is that "suburban sprawl undermines, or cancels, the benefits of urban population density.
Indeed, if you look at the map of Arizona as a whole, the suburbs of Phoenix and Tucson are what stand out.
Check out all the details of the study here.
Send feedback and tips to the author.
Follow Matthew Hendley on Twitter at @MatthewHendley.