One clear day last spring, Katharine Hayhoe walked into the limestone chambers of the Austin City Council to brief the members during a special meeting on how prepared the city was to deal with disasters and extreme weather. A respected atmospheric scientist at Texas Tech University, the 43-year-old had been invited to discuss climate change, and she breezed through her PowerPoint slides, delivering stark news in an upbeat manner: unless carbon emissions were swiftly curbed, in the coming decades Texas would see stronger heat waves, harsher summers, and torrential rainfall separated by longer periods of drought.

“Why do we care about all of this stuff?” Hayhoe asked. “Because it has huge financial impacts.” The number of billion-dollar weather disasters in the United States had ballooned from one or two per year in the eighties to eight to twelve today, Hayhoe explained as she pulled up a slide with a map of the country. “Texas is in the crosshairs of those events, because we get it all, don’t we? We get the floods and the droughts, the hailstorms and the ice storms, and even the snow and the extreme heat. And we get the tornadoes, the hurricanes, and the sea-level rise. There isn’t much that we don’t get.”

Soon afterward, Don Zimmerman, a conservative councilman who, before being elected, regularly sued the city over tax increases, declared from his seat on the dais that climate change was a “nebulous” and “foolish” field of study. Zimmerman, wearing a banker’s collar and projecting an officious air into the room, continued, “We have maybe thirty years of satellite data, and the world is maybe millions of years old. I have a really visceral reaction against the climate-change argument, for the simple reason that when you look back in time, there have been dramatic climate changes before humanity ever existed.

“The worst thing that can be done to humanity is put government bureaucrats in charge of carbon dioxide emissions,” he said as Hayhoe listened politely. “You don’t have to be as smart as a fifth grader to know that what causes the climate is the sun. I have people tell me, ‘Carbon dioxide warms the earth.’ No, it doesn’t. The sun warms the earth, and there is more energy in our sun than humanity can comprehend.” Zimmerman then insisted that the sun didn’t need “a permit from the EPA” to emit solar flares.

An uncomfortable silence settled over the chamber for a moment before Hayhoe joked, “I think if the EPA could be in charge of the sun, that could create bigger problems than we have today.” She then proceeded to gut Zimmerman’s arguments. “A thermometer is not Democrat or Republican, and when we look around this world, it’s not about trusting what our thirty-year-old satellites say. It’s about looking at 26,500 indicators of a warming planet, many of them we can see in our own backyards,” she said. The climate was not changing because of orbital cycles, which bring about ice ages, Hayhoe maintained. “The Earth’s temperature peaked eight thousand years ago and was in a long, slow slide into the next ice age until the Industrial Revolution,” she said. Instead of being in this cooling period, the planet had seen its average temperature steadily rise. The sun was also not the culprit: “If the climate were changing because of the sun, we’d be getting cooler, because energy from the sun has been going down over the last forty years,” she said.

But Zimmerman, it seemed, had no use for facts, and after the meeting he continued to harangue Hayhoe. The encounter, however, came as no surprise. In fact, it was depressingly familiar to Hayhoe, who has auburn hair, hazel eyes, and a calm, affable nature that is reminiscent of an excellent physician’s bedside manner. And she often likens herself to a doctor, but her patient is the planet. After taking its temperature, she feels compelled to report her diagnosis: because of man-made carbon emissions, the earth is running a fever. She knows that this message doesn’t always find a receptive audience. Over the past fifteen years, climate change has emerged as one of the most polarizing issues in the country, ahead of guns, the death penalty, and abortion. And there is no group that is more unconvinced of climate change’s reality than evangelical Christians, who primarily identify as conservative Republicans. As Brian Webb, the founder of the faith-based Climate Caretakers, recently told Religion News Service: “The United States is the only industrialized country in the world where denial of climate change has become inextricably linked to a dominant political party.”

All of which puts Hayhoe in a unique position. A co-author of the last two National Climate Assessments and a reviewer on the Nobel Prize–winning Intergovernmental Panel on Climate Change, Hayhoe—the daughter of missionaries and the wife of a pastor—is herself an evangelical Christian. In her talks, she uses the Bible to explain to Christians why they should care about climate change and how it affects other people, from a poor family on the island nation of Kiribati who will be displaced by rising sea levels to an elderly couple in Beaumont who can’t afford to pay for air-conditioning in Texas’s increasingly sweltering summers. As she puts it, “The poor, the disenfranchised, those already living on the edge, and those who contributed least to this problem are also those at greatest risk to be harmed by it. That’s not a scientific issue; that’s a moral issue.”

Photograph by Clint Spaulding/Patrick McMullan/Sipa USA (Sipa via AP Images) (Gala)

Hayhoe maintains a dizzying schedule. In the past year, she has attended the historic United Nations climate summit in Paris, traveled to the edge of Hudson Bay, in Canada, to witness the annual polar bear migration, curated a special Good Housekeeping issue on climate change, and appeared onstage in New York with Gloria Steinem at a talk at the Rubin Museum of Art. That’s in addition to teaching her graduate-level seminars, serving as a co-director of Texas Tech’s Climate Science Center, and publishing seventeen scientific papers. (Travel is essential for Hayhoe’s job but to do her part—and perhaps head off criticism about her carbon footprint—Hayhoe buys carbon offsets to reduce the impact of her trips.) One warm afternoon in October, on a day spent in Lubbock between visits to Colorado and Houston, Hayhoe spoke at a Phi Beta Kappa ice cream social inside Texas Tech’s Hall of Nations, a room draped with the flags of 190 countries and featuring a glossy terrazzo map of the world on the floor. The crowd, mostly professors from across the university’s departments and a smattering of students, dug into Styrofoam bowls of vanilla and cookies and cream as Hayhoe, who was wearing a red top and flowing linen pants, began her speech.

“I’m a professor here at Tech, and what I’m going to talk about today is not my research. I’m going to talk about the experience that I have talking about my research. Now, most of you are not going to have the same experience I do. If you study literature, you don’t have to spend a lot of time convincing people that books are real. If you study engineering, most people will agree that engineering is real and it’s an important part of our society. But I study something that about half of the country and much more than half of Texas thinks is a complete hoax,” she said. “Many people view having climate science at Texas Tech as similar to having a Department of Astrology. But we don’t use crystal balls, we use supercomputers; we rely on physics, not brain waves.”

The study of climate science dates to 1824, when French physicist Joseph Fourier discovered what would become known as the greenhouse effect, in which gases trapped in the atmosphere absorb heat and raise the temperature of the planet. It took 35 more years for John Tyndall, an Irish chemist, to pinpoint carbon dioxide as one of the heat-trapping gases in the earth’s atmosphere. And in 1896, a Swedish chemist named Svante Arrhenius declared that burning coal contributed to the greenhouse effect, after spending almost 2 years calculating (by hand!) how increasing carbon dioxide concentrations raised the earth’s temperature. So the basic science, as Hayhoe often points out, has been settled since before the start of the twentieth century. Today, there is robust scientific consensus that global warming is “real, caused by humans, and dangerous”; a study found that 97 percent of climate scientists agree that anthropogenic climate change is happening, and many scientific organizations have issued statements that it is a threat.* The Department of Defense calls climate change a “threat multiplier,” because it exacerbates existing problems. And the year 2015 was the warmest on record, breaking the previous mark, which was set in 2014.

So why is climate science greeted with so much skepticism? Part of the reason can be attributed to the way the topic is often handled in the media. On cable news, two people from opposite sides of the debate are typically paired to argue about the subject, but that can lead to a false equivalency between scientists on the one hand and paid spokesmen on the other. As historians Naomi Oreskes and Erik M. Conway chronicled in the book Merchants of Doubt, some of the most prominent climate-change skeptics are the same politically conservative scientists who were previously funded by Big Tobacco to spread falsehoods about cigarettes. Their employer this time around? The fossil-fuel industry.

And part of the reason is the suspicions that conservatives have of government intervention. Hayhoe has found that some people don’t reject the reality of climate change because they disagree with the science but because they fear that the solutions will upend their lives. This seems to be the case for U.S. senator James Inhofe, a Republican from Oklahoma, who once told journalist Rachel Maddow, “I thought it must be true until I found out what it would cost.” That day at Tech, Hayhoe recounted an anecdote about an experience she’d had speaking to a group of water managers for the Brazos River a few months back. At the end of that talk, an older man stood up and said, “Everything you said makes sense, but I don’t want the government telling me where to set my thermostat.”

Some critics feel so threatened that they resort to ad hominem attacks on climate scientists. Hayhoe receives a steady stream of hate mail, which she files away in a special folder. When I asked her when this started, she replied, “The first time I was ever quoted in a newspaper article.” The ugliness reached its height in 2012, during the presidential race. At the time, Hayhoe was writing a chapter on global warming for a book Republican hopeful Newt Gingrich was co-authoring about the environment. Rush Limbaugh mentioned it on his radio program, dismissively referring to Hayhoe as a “climate babe.” A few days later, an Iowa voter buttonholed Gingrich on camera to ask him about it, and Gingrich swiftly replied, “That’s not going to be in the book. We didn’t know that they were doing that—we told them to kill it.” Hayhoe took to Twitter to respond: “What an ungracious way to find out, eh? Nice to hear that Gingrich is tossing my #climate chapter in the trash. 100+ unpaid hrs I cd’ve spent playing w my baby.”

Most of the time, she laughs these incidents off. “I got one today that was exceptional,” she told me in late September, as we sat inside the Climate Science Center. “Most of the stuff is rambling, but this one was not. Someone wrote on Facebook, ‘She is a lying lunatic, and probably a witch.’ That was very concise,” she said with a grin. But sometimes the comments veer into violent territory. Hayhoe recalls one email that prompted her to call authorities. “You are a mass murderer and will be convicted at the Reality TV Grand Jury in Nuremberg, Pennsylvania,” the email began. “After the Grand Jury indicts you, I would like to see you convicted and beheaded by guillotine in the public square, to show women that if they are going to take a man’s job, they have to take the heat for mass murder.” But most of the time, Hayhoe doesn’t let such vitriol drive her to despair, though dealing with it can be exhausting. “What frustrates me the most, and what I find difficult not to take personally, is how much of the hate mail comes from so-called Christians.”

That bile is something Hayhoe never anticipated when she was applying to graduate school 22 years ago. A native of Toronto, she had double-majored in physics and astronomy at the University of Toronto and spent every clear night one summer gazing through the telescopes on top of the physics building. She found that the astronomer’s life appealed to her and planned to study that in graduate school. Then she took a climatology class her junior year. “Until I took that course, I did not realize that climate change is affecting everything, from poverty to biodiversity to health, and so you can’t fix any one of them if you leave climate change out of the picture,” she told me. She also realized that her background in physics had perfectly positioned her to study climate modeling.

If she was going to leave astronomy behind, Hayhoe wanted to do policy-relevant climate science. When she was considering graduate programs, she was thrilled to learn that Don Wuebbles, who had been instrumental in addressing the chlorofluorocarbon problem in the eighties, was the new head of the department of atmospheric science at the University of Illinois Urbana-Champaign. He would serve as her adviser for both her master’s degree and her doctorate. Under Wuebbles’s guidance, Hayhoe eventually began focusing on statistical downscaling, which was still a relatively new field when she started graduate school, in 1995. “There was very little of this being done at the time,” Wuebbles recalled recently, “and the methods were not capturing the full extent of the science, so she set about to develop a new technique and very successfully did so. She’s brilliant.”

Statistical downscaling involves combining historical weather observations with global-climate models to better predict what the future could look like in a particular place. “The local environment, whether it’s hilly or flat, with crops or forest, urban or rural, modifies the weather patterns we get,” she said. “So, for example, if we had identical high-pressure systems over Lubbock and Houston, it would mean something different for the temperature, for the humidity, for the rainfall patterns.” Hayhoe also tries to see if the global models reflect real-world conditions on the ground. “When we get an El Niño, we see a very wet winter from here in Lubbock all the way across to Florida. Do the models pick that up or not? We need to know,” she explained.

Hayhoe runs simulations on a supercomputer, then she combs through the data to interpret the output. On a practical level, this means Hayhoe exists in a world of numbers, thousands upon thousands of lines of them. A single file dealing with one variable—say, temperature across the country over the next hundred years—can be almost five gigabytes in size. And she runs these simulations for multiple variables and scenarios on multiple climate models. (Some 42 global-climate models exist today, run by labs around the world.) These reams of data are shapeless until she translates them by writing code. “What a lot of people don’t realize is that the most important skill any climate scientist has is programming,” she told me over pizza in Lubbock one afternoon last fall.

Hayhoe has used downscaling in her consulting work for the cities of Washington, D.C.; Boulder; and Chicago, as well as federal entities, including the Department of Defense and the U.S. Fish and Wildlife Service. She helps analyze problem areas, such as sewer overflow during heavy rain or warped train rails during heat waves, and tries to pinpoint how often those things will be a problem in the future, based on changing climate patterns. In 2004 Hayhoe was an author on a paper that examined California’s future from different angles, from water supply to agriculture to tourism. She was heartened when, a few months later, that research prompted Governor Arnold Schwarzenegger to sign an executive order limiting greenhouse-gas emissions. He was the first governor to do so. “When Schwarzenegger signed that bill, he had the authors from California standing in a semicircle behind him. The reason why I left astrophysics is to do policy-relevant research, and when I saw that picture, I thought to myself, ‘I did it. This works.’ ”

Hayhoe’s scientific credentials are impeccable, but what has made her an international star are her skills as a communicator. John Abraham, an associate professor of thermal sciences at the University of St. Thomas, in Minnesota, has called her “one of the best climate communicators in the world.” Abraham told me, “She is extraordinary at relaying very complex topics into language that other people can understand, without speaking down to them. The other thing she’s good at is hearing questions. We all listen, but she has this innate ability to understand the perspective of the person making the inquiry,” he said. “She has this knack for honestly presenting the science but doing it in a disarming way for people who are often anti-science.”

Photograph by AP Photo, Abilene Reporter-News/Nellie Doneva

One mild Friday in early October, I flew to Houston with Hayhoe and her eight-year-old son, who spent the short flight absorbed in the game Minecraft on his iPad while Hayhoe tapped away on her laptop. She was to give a keynote speech at Memorial Drive Presbyterian Church, a collection of limestone buildings nestled between pine trees in one of Houston’s most affluent neighborhoods. The weekend symposium was called “Faithful Alternatives to Fossil Fuel Divestment.” Hayhoe arrived with some tough talk for her audience. “There’s no way to sugarcoat this, and I wish I could, because I know I’m in Houston, but the way that we get our energy does matter. If we continue to rely only on fossil fuels, we’re going to end up on a very different pathway than if we gradually and sensibly transition to clean and renewable energy that we can grow here in Texas—and that many of our energy companies are already investing in very heavily.”

The conference was organized in response to the Presbyterian Church (USA)’s proposal to divest church resources from fossil fuels, a move the Houston chapter had rejected as a symbolic one that unfairly vilified the people who work in the fossil-fuel industry. The group instead proposed that the national organization take steps to reduce its carbon footprint and advocate for a carbon tax. Hayhoe, too, is a proponent of putting a price on carbon and letting the markets sort it out. She thinks that a reasonable tax on gasoline would be around 6 cents a gallon. “Regulations just get more and more complicated, and you have to hire new people to deal with them,” she explained. “It gets expensive and difficult to plot your strategy, but any business–from the ma-and-pa shop around the corner to the biggest multinational in the world–knows what to do with a simple price change. Business is all about maximizing profit and minimizing costs. So in a sense, putting a price on carbon just frees up business to do what it does best.”

But the most revealing part of her talk centered on why Christians should care about climate change. To lead into this subject, Hayhoe flipped to a slide with a quote from John Holdren, President Obama’s science adviser: “We basically have three choices: mitigation, adaptation, or suffering. We’re going to do some of each. The question is what the mix is going to be. The more mitigation we do, the less adaptation will be required and the less suffering there will be.” Suffering, Hayhoe said, is not a word often deployed by scientists. “As scientists we don’t know a lot about suffering, but as Christians we do. And we know that part of the reason we’re here in this world is to help people who are suffering.” And that suffering will not be meted out proportionally: if global warming continues unchecked, the poor—whether they’re in Houston’s Fifth Ward or in low-lying areas of Bangladesh—who have contributed least to carbon emissions will feel the most pain, from enduring more-intense heat waves to paying the higher food prices that will accompany failed crops. Throughout the Bible, God charges Christians to serve others, Hayhoe said, from Genesis, where God makes man in his image so that he can be responsible for every living creature on earth, to 1 Peter 4:10: “ ‘Each of you should use whatever gift you have received to serve others, as faithful stewards of God’s grace in its various forms.’

“We’ve been given this commandment to love others as Christ loved us,” Hayhoe said as a slide quoting John 13:34–35 flashed on the screen: “ ‘Let me give you a new command: love one another. In the same way I loved you, you love one another. This is how everyone will recognize that you are my disciples—when they see the love you have for each other.’ ” She continued: “You can see, you just go through the Bible for verse after verse. They’re not verses about climate change; they’re not verses about the environment. They’re verses about our attitudes and perspectives to other people on the planet. We are to be recognized for our love for other people.” The members of the crowd nodded along in agreement as she spoke. The year 2015 was a good one to be proclaiming this message: in June, Pope Francis sent out his 192-page papal encyclical imploring the world’s 1.2 billion Catholics to care about climate change, and in October, the National Association of Evangelicals issued a similar call to action.

Hayhoe can speak honestly about suffering because of a lesson she learned when her parents became missionaries and moved the family to Colombia when she was nine. There, she witnessed true poverty. Her father would travel to remote villages to speak at tiny churches, and she remembers hearing stories of landslides washing away homes after heavy rains. She now recognizes that these early memories of poverty and vulnerability have informed her work. Hayhoe was raised as a member of the Plymouth Brethren, a conservative, evangelical offshoot of the Anglican Church that emphasizes reading the Bible and interpreting it for oneself. This lent itself well to science, Hayhoe told me. “My dad was very much of the perspective that the Bible is God’s first book and nature—creation—is God’s second book.”

Though Hayhoe has always been serious about her faith, connecting with groups of fellow Christians about climate change was not something she did before moving to Texas. In 2006 she and her husband, Andrew Farley, relocated from South Bend, Indiana, to Lubbock, one of the most conservative cities in the country, so that they could both take jobs at Texas Tech, he as a linguistics professor, she as a researcher. He also became the pastor at a small nondenominational church on the southwest side of town, now called Church Without Religion. People were surprised when they learned what the pastor’s wife did, and Farley started getting lots of questions about it. And at Texas Tech, the invitations for Hayhoe to speak about climate change started rolling in. The volume of these questions and the lack of resources to point people to spurred her and Farley to write a book together, A Climate for Change: Global Warming Facts for Faith-Based Decisions. The questions they tackle in the book were familiar territory for the couple, who had met through a Christian organization while in graduate school. A few months into their marriage, Hayhoe realized that Farley, who had grown up in a conservative household in Virginia, did not think climate change was real, and they began vigorously debating the topic. “It took about two years, but now we’re on the same side,” she said.

But beyond just speaking to Christian groups, Hayhoe prides herself on being able to talk to anyone with an open mind about the reality of climate change. She bemoans the fact that global warming has come to be viewed as a niche environmental issue. “To care about climate change, all you have to be, pretty much, is a human living on planet Earth. You can be exactly who you are with exactly the values you have, and I can show you how those values connect to climate change,” Hayhoe told me.

Hayhoe’s first step is always to “genuinely bond over a shared value,” with an emphasis on that shared value’s being genuine. “The key is not to pretend; we can all smell someone who is not genuine a mile away,” she said. “If I’m talking to farmers or ranchers or water managers, I start off by talking about what we all care about, which is making sure we have water. And that, for many Texans, is almost as strong of a value as whatever it says in the Bible.” Her next step is to connect that issue to climate change. So when talking about water, she describes how climate change is changing rainfall patterns. “We’re getting these heavy downpours, and then we’re getting longer dry periods in between, and our droughts are getting stronger because the warmer it is, the more water evaporates out of our lakes and rivers and our soil,” she said. She tries to end her talks with solutions that inspire people, ranging from the personal (measuring your carbon footprint and installing energy-efficient light bulbs) to the large-scale (putting a tax on carbon). Hayhoe herself is most excited by the efforts of Elon Musk, the CEO of Tesla Motors and founder of SpaceX. “If I had to pick one person to save the world—and I don’t think any one person will but if I had to pick one—it would be him.” She is excited about the battery packs that Tesla is developing, declaring energy storage the “single technology that will make the most difference.”

Ultimately, she does not care whether people agree with the science, so long as they take action. She compares this to a battle waged in the mid-1800’s, before the germ theory of disease gained widespread acceptance, when a Hungarian physician urged other doctors to wash their hands and instruments before delivering babies. As doctors changed their habits, fewer and fewer women died from “childbed fever.” “I don’t care if they thought germs are imaginary, so long as they washed their hands,” she said. The same is true for climate change, in Hayhoe’s mind. If people start using more-efficient light bulbs or driving more-fuel-friendly cars, it doesn’t matter what they think about the science.

Hayhoe is coy about her own personal politics, and this air of mystery is useful to her. When I asked her about another Canadian-born Texan, climate-change skeptic and senator Ted Cruz, she demurred. She’s a U.S. permanent resident but not a citizen, so she can’t vote in the presidential election, and she seems to enjoy the level of remove this gives her from American politics. “It helps me not to pick sides, because people always ask if you’re Democrat or Republican, and I’m neither. I can’t be,” she told me. “I appreciate the solutions that some Republicans are starting to advance, and I appreciate the fact that Democrats accept the science. But it’s become so polarized that the good people on both sides are being marginalized.” Whoever the next president is, Hayhoe hopes he or she will honor the commitments made at the climate summit in Paris last year and also put a price on carbon.

Hayhoe’s religious background led NOVA’s Secret Life of Scientists and Engineers to dub her a “climate change evangelist” in 2011, and the label has stuck, though she is lukewarm on it. “An evangelist is someone who spreads good news, and I feel like I’m not really evangelizing. I feel more like a Cassandra, or an Old Testament prophet spreading bad news, saying, ‘If thou dost not change from thy wicked ways and repent, thou shalt reap the harvest of thy deeds.’ ” But when Hayhoe talks, she doesn’t sound so pessimistic. That’s a strategic choice, as she realizes that doom and despair won’t motivate others to act. For that, you need hope. “You have to offer people a vision of what the world could look like if we could wean ourselves off fossil fuels, if we could have a clean-energy economy,” she said. “We would all want to live in that world.”

Lyndon Baines Johnson was at his ranch outside Johnson City recuperating from gallbladder surgery on November 5, 1965, when his science advisers published a 317-page report warning about the dangers of air pollution. Tucked away in an appendix were 23 pages about atmospheric carbon dioxide. “Through his worldwide industrial civilization, Man is unwittingly conducting a vast geophysical experiment,” the report states. “Within a few generations he is burning the fossil fuels that slowly accumulated in the earth over the past 500 million years.” This additional carbon in the atmosphere would, over time, raise the earth’s temperature, slowly melt the antarctic ice cap, and lead to increased ocean acidity, the report proclaimed. “The climate changes that may be produced by the increased CO2 content could be deleterious from the point of human beings,” the report concluded.

Fifty years later, Hayhoe gave the capstone presentation at a daylong symposium in Washington commemorating the first time a president was warned about the danger of climate change. “As several have already said today, we are conducting an experiment with our planet on a scale that has never before been attempted,” she said, echoing the words of the report. The climate models that scientists now use churn out petabytes of data—which is something like, in Hayhoe’s words, “twenty million four-drawer filing cabinets full of text”—that then need to be analyzed to see how these changes will manifest in particular locales. “What’s the point of doing all of that modeling and all of that analysis if we don’t understand how it’s going to affect the system right here that we care about?”

Would LBJ even recognize the future Texas predicted by these models? In the past fifty years, temperatures in Texas have risen half a degree per decade and are set to rise at least 3.5 degrees by mid-century if global emissions aren’t slashed. “Our average summer could look like 2011 within my lifetime if we continue on our current pathway,” Hayhoe told an audience in October, referencing that scorching summer when much of Texas saw more than one hundred 100-degree days. Austin could feel more like Scottsdale, Arizona. Rainfall patterns are shifting, so the state will face longer dry spells punctuated by more bouts of heavy rain. In West Texas, farming and ranching communities have thrived in the semiarid environment by pulling water from aquifers. But as the aquifers dry up, these communities are relying more on rainfall, just as that rainfall is becoming less likely and droughts are getting more intense, Hayhoe said. In LBJ’s beloved Hill Country, this means increased risk of fire. Humans are the ones igniting the fires, but climate change is making them worse by providing the ideal dry conditions they need to spread. On the Gulf Coast, where a quarter of the state’s 27 million people live, sea levels are already eight inches higher than they were a hundred years ago and are set to rise an additional one to four feet by the end of the century. And then there’s the danger from stronger hurricanes fueled by record-breaking ocean temperatures.

Texas leaders, however, seem unwilling to tackle the problem or even admit that it exists. Governor Greg Abbott has long voiced skepticism about the science of climate change, telling the editorial board of the San Antonio Express-News during his gubernatorial campaign that the climate has always changed over time and further study was needed. “We must be good guardians of our earth, but we must base our decisions on peer-reviewed scientific inquiry, free from political demagogues using climate change as an excuse to remake the American economy,” he told the newspaper. As attorney general, Abbott made a habit of suing the Obama administration, oftentimes over regulatory issues relating to climate change. His successor, Ken Paxton, is continuing that tradition, joining a lawsuit in October over the administration’s Clean Power Plan, which calls on states to curb emissions by phasing out coal plants and shifting to natural gas and renewables. The plan would require Texas to decrease its coal power capacity by 4,000 megawatts, or 25 percent, and Paxton has likened this to the EPA’s mounting a “war on coal and fossil fuels.”

In such a milieu, efforts to incorporate climate change into planning at the state level have fallen flat, and bills that attempt to address it have gone nowhere in recent years in the Legislature. “At the state level, in some circles, climate change is still a taboo subject,” John Nielsen-Gammon, the state climatologist, told me. This leaves cities to do their own resilience planning. Meanwhile, entities such as the Electric Reliability Council of Texas, the operator of the state’s electric grid, are not taking climate change into account when developing their projections for load growth, which could lead to problems as the mercury creeps upward.

In Congress, Texans are some of the most vocal climate-change skeptics. Congressman Lamar Smith, a Republican from San Antonio, has used his chairmanship of the House Science, Space, and Technology Committee to tussle with federal agencies over their climate-change research, going so far as to subpoena the scientists who conducted a study with a conclusion he disagreed with and demand their emails. (Smith, it is worth noting, has received more than $600,000 in campaign donations from the fossil-fuel industry over his 29 years in Congress.) And then there’s Cruz, who in December held a three-hour Senate hearing titled “Data or Dogma? Promoting Open Inquiry in the Debate Over the Magnitude of Human Impact on Earth’s Climate,” at which he claimed that there was a lack of scientific consensus on global warming.

Hayhoe is hopeful that as green energy gets cheaper, more people will begin using it. “Texas is unique, in that it is one of the states that have the most to lose economically from climate-change impacts, but Texas also has the most to gain by transitioning to a clean-energy economy,” Hayhoe told me one day in her office on campus, a cluttered, windowless space. The room’s sole decorative flair, a papier-mâché arctic fox that was a Christmas present from her young son, sat perched on a shelf.

If Texas were its own country, it would be the seventh-most-prolific emitter of carbon dioxide in the world. As it stands, Texas is the number one emitter in the U.S.; it released some 641 million metric tons of carbon dioxide into the atmosphere in 2013, almost double that of California.

But the state also has a seemingly boundless potential for green energy. Texas leads the nation in wind generation; turbines produced a full 10 percent of the state’s power in 2015. By 2030, that number is forecast to jump to 37 percent. One night last September, supply of wind power was so plentiful and demand was so low that the spot price of electricity went negative for a few hours. Solar installation has lagged behind, but when it ramps up, there’s enough capacity just in the area a hundred miles square** between Plainview and Amarillo to light the entire United States, as Hayhoe likes to point out. In Pecos County alone, companies have plans to invest $1 billion in large-scale solar energy farms. “Texas understands energy. Energy is a Texas thing,” Hayhoe told me. “We have the land we need to do this, as well as the technology and entrepreneurial spirit. I wish that the whole state could see that this is an opportunity for a better future.”

*Clarification: This sentence has been edited to clarify the conclusions of the study and include the fact that a number of scientific organizations have issued statements about global warming being a threat.

**Correction: An earlier version of this sentence incorrectly referred to this area a hundred square miles. We regret the error.