This story is part of a series focusing on climate change in key Senate races on the ballot in November.

At a Glance:

• Incumbent Sen. Martha McSally, a Republican, has said little about climate and  energy since being appointed to fill the late John McCain’s seat in 2019.

• Retired astronaut Mark Kelly, a Democrat who supports climate action, is favored to win Arizona’s special election to complete the remaining two years of McCain’s term.

• Nearly two thirds of Arizonans say they want steps taken to address climate change. And that was before enduring the state’s hottest summer on record.

Republican incumbent Sen. Martha McSally hasn’t been talking much about climate change and the environment in her 2020 campaign fight against Democratic challenger, Mark Kelly. But the race has been getting a lot of attention nationally because, if Kelly wins, Democrats will be making a significant stride toward flipping control of the Senate and making climate change a national priority.

McSally, the first woman to pilot an American warplane into combat, serves on the Senate Energy and Natural Resources Committee. But her efforts on environmental issues have been low profile. Instead, she focuses on Trump administration priorities like health care, the military and border issues.

“Our environment and the Earth’s climate are changing and there is likely a human element to it,” she responded in an Arizona Republic questionnaire on climate change during her unsuccessful 2018 Senate run against Democrat Kyrsten Sinema, who openly acknowledges climate science and action.

McSally credited technology that taps into “affordable abundant resources” for reducing U.S. carbon emissions, “not a heavy handed government approach.” And she named the Obama administration’s Clean Power Plan and the Waters of the United States—regulations that Washington Republicans have rolled back in recent years—as examples of ”federal overreaches that further burden Arizona’s small businesses and farmers and harm those in poverty with increased utility bills.” 

A two-term congresswoman before joining the Senate, McSally has sponsored legislation to streamline renewable-energy permitting on federal land and to allow the Interior Department to implement drought contingency plans for the Colorado River. She also was a co-sponsor of bills to provide incentives for energy storage and voted for the landmark Great American Outdoors Act.

Although McSally does not mention climate change or environmental issues on her web page, she has been a co-sponsor of a bipartisan bill to revitalize nuclear power as a buffer against harmful climate impacts. Meanwhile, her Senate web page touts her vote against the Green New Deal, calling it “a pipe dream that would bankrupt hardworking Arizona families.”

“We do have to address the issue of climate, and water is so important for Arizona—it’s our lifeline,” she said in a 2018 debate with Sinema. Then she abruptly pivoted to a topic she said had been neglected, veterans affairs.

Arizona cities like Tucson are adopting their own climate plans instead of waiting for help from Washington. Mayor Regina Romero, a Democrat who made climate resilience a central theme of her campaign last year, has been behind efforts to step up water conservation, tree planting and expanding clean energy.

She called climate change a public health problem as well as an environmental one that harms Black and brown children, and poor and older Arizonans disproportionately. And, while she avoided commenting on McSally directly, she noted that, as heat waves, water shortages and other climate impacts threaten Arizona citizens, cities cannot address climate on their own.

“We need to send another senator [to Washington] who will protect Arizonans,” she said.

‘Make No Mistake: We Have No Place Else to Go’

Kelly has highlighted how his views on climate change and the environment have been influenced by space travel. The League of Conservation Voters is backing Kelly’s campaign with money and the Grand Canyon Chapter of the Sierra Club has given him its endorsement for his commitment to “commonsense climate solutions,” especially in disadvantaged communities.

A first-time candidate married to Democrat Gabby Giffords, a former congresswoman who was seriously wounded in a 2011 shooting, Kelly is also known for supporting guns-safety policies. 

Like McSally, Kelly is a former combat pilot who has said he does not favor the Green New Deal. But, from the start of his campaign, he’s talked about using science and data as tools to help tackle climate change and allow his state “to lead in the transition to a renewable economy.”

“Make no mistake: We have no place else to go,” the Democrat said during an interview on the television talk show The View, recalling the deforestation he saw from space in the decade between his first space shuttle flight and his fourth. 

“That’s a lot of carbon coming up into our atmosphere, and it’s going to heat up our planet,” he said. “We’ve got to figure out a way to get away from fossil fuels to more renewable energy, and I think we’ve got a decade or so to figure this out, but we can’t continue to wait.”

What might be surprising is that climate change isn’t a marquee issue for Arizona voters this year, even though July, August and the summer as a whole shattered heat records. The number of heat-related death investigations more than doubled compared with last year in the county where Phoenix is located, the largest in the state.

Meanwhile, Colorado College’s State of the Rockies poll from February found that 80 percent of adults in Arizona say that clean water, clean air, wildlife and public lands influence their voting decisions and that 73 percent of adults worry that water supplies in the West are becoming more uncertain.

“Arizona itself is a state that can’t really turn a blind eye to climate because of what’s happening there,” as it warms faster than any other state in the Lower 48, said Lindsay Bourgoine, who leads the political action committee of the climate-advocacy group, Protect Our Winters.

“We really have to think about how we elect a climate majority in the Senate,” she added, noting that the current Republican-led Senate won’t take up legislation to reduce greenhouse gas emissions. “So we’re definitely interested in seeing Mark Kelly prevail to have a climate majority in the Senate.”

The Takeaway:

Some say McSally is helping to shift Arizona from purple to blue. The Lincoln Project, a Republican PAC formed to take down Trump Republicans, has been attacking her for “going full Trump.” The incumbent senator represents a dramatic contrast to the man whose seat she wants to keep, the late Sen. John McCain, a Republican senator who co-sponsored early, bipartisan climate legislation. McSally continues to trail in the polls, and the Cook Political Report projects that she’s the sole Republican in a Senate race nationwide that’s leaning Democratic.

An earlier version of this graphic reversed the black bars showing the proportion of donations from the energy sector. The black bars now accurately match the donation proportions.