Scorching Phoenix may be out of position to deal with climate change
On March 21, during a period of record-breaking heat in the Southwest, Phoenix tied a 45-year-old record after temperatures topped 90°F for the ninth consecutive day.
Looking over the past 50 years of average temperature data shows that seven of the eight fastest warming cities are in the West. Phoenix, along with Las Vegas and Reno, is leading the way, warming at least 5°F since 1965. While the urban heat island may play a role, this pattern of warming — coupled with the trend toward rapidly warming nights — is consistent with the general warming coming from greenhouse gases.
One of the strongest findings of climate science is that global warming amplifies the intensity, duration and frequency of extreme heat events.
Today, Phoenix is a horizon of asphalt, air conditioning and historic indifference to the pitfalls of putting 1.5 million people in a place that gets just 8 inches of rain a year and where the temperature routinely exceeds 100 degrees.
Now, however, the city faces a reckoning. It is called climate change, and it is expected to further expose the glaring gap between how the city lives and what it can sustain. The future, scientists say, will be even hotter and drier, the monsoons more mercurial. Summertime highs could reach 130 degrees before the end of the century — think Death Valley, but with subdivisions.
“My colleagues and I wonder about the future habitability of Phoenix all the time,” said David Hondula, a climatologist who studies the impact of heat on health at Arizona State University.
The average high here in August now exceeds 104 degrees, but 110 is not uncommon, and the temperature has hit 120 more than once. In summer 2016, a study by Climate Central and the Weather Channel found that the average temperature in Phoenix had increased 1.12 degrees over the previous half a century. No major city saw temperatures rise more — and, of course, no major city regularly reached such scorching highs in the first place.