South Mountain Park in Phoenix is the largest municipal park in the United States at nearly 17,000 acres. Zahira Ortega and Daniel Garcia, both of Avondale, enjoy the panoramic view of the Valley from Dobbins Lookout. Photo: Cheryl Evans / The Republic

By Steve Hanley
29 September 2017
(CleanTechnica) – Phoenix, Arizona, is America’s fifth largest city. As you fly in to Sky Harbor airport, the city stretches from horizon to horizon beneath you. It’s hot in Phoenix. Always has been. The people who live there laugh about it, calling it a “dry heat” because there is so little humidity in the air. Be that as it may, living in Phoenix without air conditioning is almost unthinkable.Its citizens transition from air conditioned homes to air conditioned cars to air conditioned offices, courts, shopping centers, and churches. For people who say they revel in dry heat, they make it a point to stay out of it as much as possible. Many of the locals rely on evaporative coolers instead of traditional air conditions. But the evaporative equipment depends on ultra low humidity — below 10% on most days. Clouds in the sky are reasons to be concerned because they signal higher than normal humidity in the air.Phoenix requires two things not found naturally in the area — electricity and water. Without both, the Phoenix of today would never have happened. Despite its abundant sunshine, Arizona has depended for decades on electricity generated by burning coal. Utilities companies in Arizona have been slow to transition to renewables, although lower prices are driving them to look in that direction.Heat is one factor that will make Phoenix less hospitable to human habitation in the foreseeable future. “It’s currently the fastest warming big city in the US,” meteorologist and former Arizona native Eric Holthaus tells Vice. A study by Climate Central finds that Phoenix will likely be three to five degrees hotter in the summer months by 2050. The average number of 100 degree days will increase from 40 a year today to more than 132 a year. To put that in some perspective, New York City currently experiences two 100 degree days a year. Climate Central expects that number to increase to 15 a year by 2050.In 2015, 85 Phoenix Maricopa County residents died from causes associated with the heat. In 2016, 130 did so. Arizona State University climatologist David Hondula tells Vice that those deaths cannot be directly tied to climate change, but he warns that increasing temperatures will require Phoenix, which is located within the county, to step up its game when it comes to “social service programs, homeless shelters, the opioid epidemic,” and other “intermediating factors. If we’re not paying attention to those at the same time we’re keeping an eye on the thermometers, we might really miss some drivers and some threat magnifiers.”Heat is not the only factor making the Phoenix area less hospitable to humans. Hondula says that lack of water could be more of a problem than rising temperatures. “As much as 20 percent of the river could dry up by 2050,” he says. The majority of the drinking water for the area comes from the Colorado River — the same source that much of southern California depends on. […]Phoenix is a cautionary tale for why rational people should begin planning now for the effects of climate change. But will they? [more]

Climate Change May Make Phoenix Uninhabitable By 2050