This article is part of a Sierra series about the 2020 election.

July was the hottest month ever recorded in Phoenix, Arizona. Then August came, and it knocked July down to second place. In July, the average daily temperature was 98.9°F. In August, it was 99.1°. This year had 50 days above 110°, shattering the previous records.  

The record-breaking summer heat is the backdrop for a red-hot Senate race that will be a crucial test of whether Democrats can take control of the chamber. Former astronaut and Democrat Mark Kelly (the husband of former US representative Gabby Giffords, who barely survived a 2011 assassination attempt) is challenging Republican senator Martha McSally, who was appointed to the seat after Senator John McCain died in 2018. Since this is a special election—and the winner will be sworn into office in November—the victor may play a role in deciding whether Amy Coney Barrett fills the Supreme Court seat of the late Ruth Bader Ginsburg. But while Supreme Court politics have dominated the final stage of the race, climate has lurked at the edge of the contest as one issue that could sway some voters.

A recent poll found that 71 percent of voters in Arizona think the government needs to do more to combat climate change. Pitching himself as a centrist, Kelly has said that he doesn’t support the Green New Deal. He has tried to frame climate change and the resultant extreme heat as a threat to Arizona’s economy and emphasizes advocating for investment in renewable energy and creating green jobs. “We could create the technology here, we can manufacture it here, we can deploy it here,” Kelly said at an October 7 debate. “It could be great for our state.”

Kelly has also talked movingly about how his experience as an astronaut gave him an appreciation for the fragility of the planet and its atmosphere. "I’ll never forget the first time I got to see our planet from low-Earth orbit, seeing this big round ball and realizing that we are really all in this together,” Kelly said at the debate. “It becomes really clear really quickly that we have no place else to go. There is no planet B. We’re not moving somewhere else someday. We have to do a better job taking care of this planet." 

McSally has a different position when it comes to climate change. While she acknowledges that the climate is changing and that there is a “human element” to it, she has adopted the classic free-market-fundamentalist position that technological innovation—not government action—is the solution to the crisis. McSally’s tenure in the Senate has been marked by broad support of President Trump’s anti-environment agenda, including voting to roll back the Clean Power Plan. The League of Conservation Voters gives her a lifetime score of just 7 percent. 

During the recent 90-minute debate, nearly all of the first hour was spent discussing health care, while only 10 minutes were spent on climate change. Kelly criticized McSally for taking oil and gas money and for voting to roll back regulations on clean air and water, which he called a “mistake.” She responded: “I want clean air and water, but what I don’t want is to hurt Arizonans … who can't afford these mandates that are coming from Washington, DC, that are not based on science.” In response to this—and allegations that he wants to “ban fossil fuels”—Kelly shot back, “I don’t know where Senator McSally gets her information from.”  

While there is widespread support for climate action, health care and the economy are the top issues for many Arizona voters. Voters’ focus on health care and economic issues has prompted some environmental groups to attempt to draw the links between extreme heat, public health, and economic inequality.   

Laura Dent, executive director of the advocacy group Chispa Arizona, a program of the League of Conservation Voters, said that Arizonans already know that the state’s bad air pollution negatively affects health by contributing to high rates of asthma. Now, the public is starting to see heat as another health threat. 

Heat-related deaths have skyrocketed in recent years. In Maricopa County, which includes the Phoenix metro area, heat-related deaths jumped from 84 in 2015 to 197 in 2019. This year is shaping up to be another record: As of September 26, there were 113 confirmed heat-associated deaths, as compared with 64 at the same time last year. 

Heat can also cause a slew of illnesses, from heat exhaustion to heat stroke. It is particularly lethal to those who are elderly, have pre-existing conditions, or are on certain prescription medications. During community conversations around heat-related illnesses and deaths, Chispa is highlighting the fact that Kelly is pushing for protections for pre-existing conditions. In contrast, McSally has voted repeatedly to undermine and dismantle the Affordable Care Act, even though she says that she is in favor of protecting pre-existing conditions.  

Heat’s negative effects are also influenced by geography and income: Neighborhoods with more low-income residents can measure 10 degrees hotter than wealthier neighborhoods do. “This super-hot summer impacted Latinos and POC [people of color] first and worst,” Dent said.

In Arizona, 24 percent of eligible voters are Latino, and they tend to live in communities that are hotter and have more polluted air. In Arizona, a recent poll found that 61 percent of Latino voters said they’ve experienced the effects of climate change in the past five years. The same poll found that 73 percent of Latino voters said that it was very or extremely important that their representatives “aggressively combat” the climate crisis.  

Extreme heat’s uneven burden does not stop at health impacts. It's an economic issue too. With everyone at home sheltering from both COVID-19 and the heat, energy usage in Arizona is up. Increased energy usage combined with the economic hardships wrought by COVID has left many unable to pay their utility bills. In the Phoenix metro area, the hardest hit are low-income communities, which tend to lack green space and have less energy-efficient homes. While utility companies have halted power shutoffs due to COVID, some residents are racking up higher and higher delinquencies. Chispa’s Dent fears that residents will be unable to pay off the delinquencies once the shutoffs resume. Energy-assistance programs that help low-income residents pay their bills have struggled to keep up with demand: In Phoenix, only 4 percent of eligible residents were covered in 2019, according to a spokesperson for the city of Phoenix. Now, as the pandemic has forced more people across income levels to seek help paying their utilities, money from the CARES act is being directed to those assistance programs.  

The outcome of the Senate race in Arizona will play a role in determining whether Arizonans get the relief they need. The Republican-controlled Senate for months has refused to pass additional COVID assistance programs, and Republican leaders have yet to unveil any kind of alternative to the Affordable Care Act they’ve spent more than a decade fighting. If the Senate stays in the hands of Kentucky senator Mitch McConnell, it’s unlikely it will approve comprehensive climate and energy legislation any time soon. 

A Senate made up of members committed to addressing the climate crisis could also take measures to cushion the blow of extreme heat. Today, most policymaking on heat effects—if it exists at all—happens at the city or county level. For example, all that data on heat-related illnesses and deaths comes from Maricopa County, which has pioneered monitoring the health impacts of heat. Phoenix has a slew of adaptive measures planned, from experimenting with reflective pavement to planting more trees, all with the goal of reducing the urban heat island effect. While not all of Phoenix’s plans have progressed toward their goals, they’re still far ahead of federal and state heat-related policies.

David Hondula, who studies the health effects of heat at Arizona State University, believes heat should be regulated at all levels of government, much like air quality is. “It is not totally unfair to say that there is close to zero governance infrastructure for heat,” Hondula said.

Projects like tree planting, energy subsidies, and weatherization—all crucial to reducing heat exposure—cannot happen without establishing a system of federal standards and local implementation, Hondula said. While he sees Arizona’s cities as “testbeds” for heat policy, he’s looking for more federal involvement.  

With less than three weeks to go until the final votes are cast, Kelly is leading in most polls, and the RealClearPolitics average puts him ahead by eight points. Arizona environmentalists know the outcome will impact climate policy at the national level, and that Arizonans have their land, health, and economy at stake.

“From Arizona’s perspective, the question for us is really what's not at stake,” Dent said. “This is the most important election of our lifetime.”

Paid for by the Sierra Club Voter Education Fund, which seeks to raise key environmental issues in the discussions around elections and encourage the public to find out more about candidates’ positions on key environmental issues.