This article was produced in partnership with AL.com, which includes The Birmingham News, The Huntsville Times and Mobile Press-Register.
As the Trump administration went about weakening vehicle fuel economy standards earlier this year, the climatologist John Christy made his own calculations of how the change would affect Earth's climate.
His conclusion: Not at all.
In an analysis he put together for the Environmental Protection Agency's elite board of outside science advisors, of which he was a member, Christy argued that Earth's climate simply wasn't that sensitive to changes in carbon dioxide. So neither the weakened federal standards, nor California's tougher standards, which the Administration repealed as part of its rollback, would make any difference.
"My analysis showed that it doesn't make a difference which rule you pick," Christy, a professor and interim dean of the College of Science at the University of Alabama in Huntsville, said in an interview. "You can have the California rule for the whole country or California accept the rest of the country's rule and the amount of carbon emissions are so tiny relative to the world, it's not going to make a difference in whatever the climate is going to do."
It's an assertion that flies in the face of mainstream science. But it is right in line with the argument that Christy has been making for 30 years, drawing on his pioneering—but hotly disputed—work on satellite temperature readings. He has argued before Congress and elsewhere that the Earth is not heating as quickly as climate models predict, and that society should not make the costly decision to curb fossil fuel consumption based on what he often describes as the "murky" science of climate change.
Christy is perhaps the most prominent of a group of climate science outsiders who have become insiders in the Trump era. He has gained a seat on the EPA's Science Advisory Board, and won a $1.5 million Department of Energy grant for his research into the contrarian notion that the Earth's climate is relatively insensitive to carbon emissions. Recently, the Trump White House offered Christy the job of chief scientist at the National Oceanic and Atmospheric Administration, but he turned it down and the post went to another scientist.
Christy's ascent to the center of influence is an example of how the Trump administration has weaponized contrarian science to deny climate change. Scientists like Christy are especially useful to Trump, allowing the president to convey the misleading message that there is a serious dispute in the scientific community over whether the Earth is experiencing dangerous warming in response to the increasing carbon dioxide levels in the atmosphere.
Although Christy's data have been corrected repeatedly and his conclusions contradicted time and again by other climate scientists, the administration has given him new clout. That platform and support may prove important in the long court battles ahead over the administration's retreat from climate policies such as the fuel economy standards. The Trump administration can argue that it followed the recommendations of science advisers like Christy to counter legal challenges by states and environmental groups who argue that the rollbacks have been "arbitrary or capricious," the legal test the courts apply to decide if a regulation should be overturned. The fossil fuel industry, which already has used Christy's work to cast doubt on the science of climate change, can add his new U.S. government-funded research to its case for slowing down climate action.
Michael Mann, a climate researcher at Penn State University, said he likes Christy, and considers him a friend, but that his statements don't match up with the actual evidence about climate change.
"John has gone on to play a contrarian role in general when it comes to the science and impacts of climate change, often downplaying the threat in a way that is not true to the actual scientific evidence," Mann said. "I wish he wouldn't do that."
An Evangelist for Fossil Fuels
Born in Fresno, Christy describes himself as a life-long weather nerd, and recalls obsessing over cloud patterns as a teenager and using the programming language Fortran to generate his own weather forecasts while still in high school in the late 1960s.
He is 69 now, with a wiry frame, a slightly bushy mustache and a quick, bounding gait. An ultra-marathon runner, he looks 69 going on 50, and still keeps in his office volumes of weather recordings dating back to his time as a teenager in California.
After earning an undergraduate degree in math at Cal-State Fresno in 1973, Christy packed his bags for Nyeri, Kenya, where he spent two years as a Christian missionary.
It was a seven-day a week job, teaching physics and math at a Baptist high school, that stretched from 7 a.m. until lights out at 10 p.m. and included cleaning and other chores on weekends.
During his missionary days, Christy said, he saw firsthand what the world looked like without easy access to energy. He believes that limiting carbon emissions in the United States would be ineffective in stopping climate change and that keeping developing nations from benefiting from what fossil fuels provide would be downright immoral.
Sitting at a small conference table in his fourth floor office at the university, Christy's eyes light up while explaining his work, a professor in the thrall of lecturing on his favorite topic.
"There's no question that carbon-based energy has made for longer, better lives," Christy said. "You know, I lived in Africa for a while and without energy, life is brutal and short. And I wish these environmentalists would go live in a country like that for a while and understand that, understand why they are going full bore on energy production."
In Christy's view, renewables like wind and solar are insufficient for the kind of energy production needed in the modern world.
"I try to tell people about why there's just not enough energy there," he said. "I can stand in the sunlight. It doesn't bother me at all. If the wind is blowing, doesn't bother me at all. That tells you right there, it has very little energy.
"But if I stood inside the boiler of a natural gas or coal fired power plant, I'd be incinerated. That's where the energy is."
Climate scientists who advocate a transition to cleaner energy say they are not arguing that poor nations should be left behind. Christy "is saying there's only one path to development and the way we did it 300 years ago is the way you have to do it today." said Texas Tech University climate scientist Katharine Hayhoe, who hosts the PBS Series "Global Weirding." And, she added, "We just know that that's not true."
"It's like saying you need Model T Fords first before you can have electric cars, or you need a party line telephone first before you can have a cell phone," Hayhoe said. "Poor countries are already leapfrogging right over fossil fuels."
Atmospheric scientist Kevin Trenberth, a former teacher of Christy's, came to part ways with him over his science and views. "He believes that any increase in the price of fossil fuels will hurt the ability of poor Africans to develop," Trenberth said in an email. "What he has totally failed to include or comprehend is that climate change hurts Africa as much or more than any other region (perhaps except Australia) because of drought and floods.
"Certainly his heart is in the right place, with great empathy for the Africans he was with," Trenberth said, "but his brain is not."
From Pastor to Teacher
Arriving back in the United States, Christy pursued a religious vocation. He earned a Master's in Divinity from Golden Gate Baptist Theological Seminary and, in 1975, married Alice "Babs" Joslin, a fellow missionary who taught English at the high school when they both were in Africa.
The couple moved to Yankton, South Dakota, on the Missouri River, where Christy served as the founding pastor of the Grace Baptist Church. Money was in short supply, so he began teaching, first at Yankton College and then at the University of South Dakota. He found that he loved it, especially teaching math and science, and took a leap of faith, uprooting his family and entering graduate school at 31.
"My wife must have thought I was crazy, because we were just barely making it in South Dakota, and I'm going down to be a graduate student for five years with two kids in Illinois," Christy said.
Christy pursued a Master's degree and then a Ph.D. in atmospheric science at the University of Illinois. One of his professors was Trenberth, who was then doing pioneering research on the interaction between the atmosphere and the oceans. When Christy embarked on a doctoral dissertation on the redistribution of atmospheric mass associated with extreme events, Trenberth became Christy's Ph.D. adviser.
"He came to me late after serving as a missionary in Africa," Trenberth recalled in an email. "His skills were rusty but he did OK work on his thesis." Christy's wife, Babs, even worked for a time for Trenberth as an administrative assistant. "So we had close ties once," Trenberth said.
The connection did not last. Trenberth moved to the U.S. National Center for Atmospheric Research in Boulder, Colorado, in 1984, and went on to become one of the world's leading experts in climate change science and modeling. Christy, who finished his doctorate at 36, embarked on a career devoted to trying to prove the climate modelers wrong.
In 1987, he accepted a job at the University of Alabama in Huntsville, one of the nation's largest research and technology centers and the home of the National Aeronautics and Space Administration's Marshall Flight Center, and set off on a 30-year roller coaster ride through the climate science community.
Christy's Innovation: Satellite Temperature Reading
In Huntsville, Christy began working with a NASA scientist, Roy Spencer. Spencer shared Christy's religious orientation—he has written about rejecting the science of evolution in favor of the creationist theory known as intelligent design, and described himself as a "Bible-believing scientist"—and Christy's skepticism over an issue that by the late 1980s was creating an upheaval in atmospheric science: climate change.
In one of their first papers together, published in the prestigious journal Science, Christy and Spencer raised questions about the global temperature record, arguing that thermometers on Earth's surface were too few, too spread out, too subject to human error and too affected by urban heat to be trusted to create a reliable record.
Drawing on Spencer's expertise from the space program, they worked together on a new method of charting temperatures, using instruments on weather satellites that had been aloft since 1978. Christy and Spencer argued that these orbiters, which circle Earth at its poles 14 times per day, could scan the entire planet and take readings at different layers of the atmosphere.
Together, they developed a technique for measuring temperatures from space—no easy feat, because there's no such thing as space-based thermometers. They calculated temperature readings from microwave radiation signals emitted by oxygen molecules at different altitudes, and captured by sensors aboard the spacecraft. It was considered a breakthrough, and earned the pair NASA's Medal for Exceptional Scientific Achievement in 1991.
In the wider world, Christy and Spencer were also getting attention—not for their technique, but for what they said it revealed. They reported that their new measurements showed that there had been no discernible climate change over the last decade. "Satellites Find No Sign of Global Warming in the 80s," said the headline on an Associated Press story carried in The New York Times. "Some experts say the earth is beginning to warm as a result of carbon dioxide and other gases dumped into the atmosphere over the last 150 years of industrial civilization," the story said. But the first space-based measurements showed only a slight temperature increase in the northern hemisphere and a slight decrease in the southern hemisphere.
"The net effect for the globe is basically zero,'' Christy was quoted as saying.
He added, in a 1993 interview, referring to the heat in urban areas from blacktop roads, "What we may be witnessing is the asphalt effect rather than the greenhouse effect."
As Christy and Spencer updated their data over time, the temperatures they recorded diverged even more from the surface temperature record. By 1995, their data indicated that the planet was, in fact, cooling, not warming.
The doubt they raised about global warming, amplified by the fossil fuel industry and other foes of climate action, has been long-lasting. Their science has not been quite as durable.
The Relentless Refutation of Christy's Science
Over time, studies uncovered layer upon layer of flaws in Christy's analysis, with his old dissertation advisor, Trenberth, chief among his early critics.
Trenberth and others showed that space-based temperature reading—far from being a precision science—involved applying complex mathematical formulas to adjust for the vagaries of satellites themselves. Satellites drift east and west, their orbits decay, they retire altogether, with new satellites taking their place. Each anomaly could skew the temperature readings in a different way.
In 1997, Trenberth and a colleague at the National Center for Atmospheric Research showed that abrupt "downward jumps" in Christy and Spencer's temperature readings coincided with changes from old satellites to new satellites, accounting for their "cooling" finding. Climate scientist Andrew Dessler of Texas A&M has explained it this way: "Suppose you are trying to watch your weight, but your scale breaks and a month passes before you buy a new one," he said. "If the new scale says you are two pounds heavier than your last reading on the old scale, does this mean you have gained two pounds? Or does the new scale just read two pounds heavier than the old one?"
A team from the California research firm Remote Sensing Systems (RSS) showed in 1998 that satellites lose altitude over time, at a rate that varies year-to-year, depending on solar activity. Christy and Spencer, the RSS team showed, failed to account for how their angle of observation changed with this orbital decay.
Although Christy and Spencer had developed "an extremely valuable air temperature record," the RSS scientists said, the satellites "were originally designed with meteorological objectives in mind, and their ability to measure very small climate variations is limited." RSS would soon begin putting together its own satellite temperature data set, obtaining consistently different results from those of Christy and Spencer.
In 2004, scientists at the University of Washington published evidence that Christy and Spencer's readings of what was purported to be the lower atmosphere—the troposphere—were being polluted by the cooler upper atmosphere, the stratosphere. The following year, the same team in Washington showed that Christy and Spencer's temperature plots were biased by the satellites' east-west drift.
Christy and Spencer responded to the critiques by adjusting their calculations, and by 1998, they had backed off their cooling finding, reporting a global warming trend apparent in their data, albeit a slight one. At one point, Christy introduced an algebraic error into his orbital drift re-calculations, making it look like the lower atmosphere warmed at night and cooled during the day. Christy then corrected that error, thanking the RSS scientists who pointed it out in a letter to Science magazine.
Christy and Spencer have insisted that with that one exception, they were not correcting errors but making the kind of improvements that have been made in all temperature records over time. "In the 25+ years that John Christy and I have pioneered the methods that others now use, we made only one 'error,'" Spencer wrote in a 2019 blog post.
Christy said his critics are unfairly attempting to use that single error to discredit his entire body of work.
He said critics ask themselves, '"How can we dismiss John Christy's science?'" and then answer, "'Well, we can talk about that time when his satellite data was found to have an error.'"
He added, "Even though it was 15 years ago and it was corrected."
Judith Curry, a climatologist who also has questioned climate models and is seen as a contrarian, says that Christy has done the kind of careful data analysis that is key to understanding past climate variability and change.
"John Christy's work was seminal in applying satellite data to interpreting global atmospheric temperature variability," said Curry, the former chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, in an email. "In addition to satellite data, Christy has done some very careful and important analysis of historical weather/climate data for the U.S. in interpreting the variability and change. He has also conducted important research on evaluating the simulations of global climate models."
But mainstream climate scientists who have analyzed the work of Christy and Spencer say the problem is more profound than a single mistake.
"The history of the UAH tropospheric temperature data sets is a history of serious scientific error," said Benjamin Santer, a climate researcher at Lawrence Livermore National Laboratory, referring to the University of Alabama in Huntsville. "Most of the serious errors in UAH temperature data have been detected by other research groups, not by UAH scientists."
Embraced by Industry, a Rift With Climate Scientists
While the debate was raging over Christy's work in the scientific community, he was accumulating a following in the fossil fuel industry and the U.S. Congress.
"Sensitive satellite measurements have shown no warming since the late 1970s," said then-ExxonMobil chief executive Lee Raymond in a speech on the eve of the 1997 Kyoto climate talks. "In fact, the earth is cooler today than it was 20 years ago."
In 2001, ExxonMobil's chief lobbyist successfully recommended that President George W. Bush's administration choose Christy to review the submissions of the U.S. team contributing to the Intergovernmental Panel on Climate Change's Third Assessment Report, an assignment that helped burnish his scientific credentials.
Christy became a frequent witness on Capitol Hill. He has testified before Congress some 20 times, typically at the invitation of Republican lawmakers looking to cast doubt on the science of human-caused climate change. When asked about warming, Republican Texas Senator Ted Cruz frequently invokes the superiority of Christy's satellite data, which shows no such trend.
Christy is adamant that he does not take money from fossil fuel companies, saying, "No one would take me seriously," if he were on Big Oil's payroll. But a wide array of Libertarian activists and groups that receive industry funding have promoted the work of Christy and Spencer, including the Western Fuels Association's Greening Earth Society, the think tank the Heartland Institute, and the Competitive Enterprise Institute.
Christy's argument has shifted from the early days of his work, when he challenged the notion that global warming was taking place. Since at least 2007, he has acknowledged that the Earth is warming, but not as quickly as the climate models predict. A team from NASA, the University of California, Berkeley, and Massachusetts Institute of Technology recently published a study showing that global sea-surface temperatures were well in line with climate models. But Christy, Spencer and others who rely on their work often display a chart that plots their satellite readings against those of the climate models that show no such agreement. It has become iconic among those who challenge climate science.
Although the chart itself has not been published, it is based on a 2007, peer-reviewed paper, of which Christy was a co-author. That paper, too, became a lightning rod for criticism. Other researchers said that if Christy had included the full range of uncertainty in both his own data and in the climate models, the projections and observations would have been shown to overlap. And in a paper published in 2008, a team of scientists from 12 institutions found that Christy and his colleagues did not account for the effect on their temperature readings of natural non-climate factors like El Niños and La Niñas.
That team was led by Santer, who had won a MacArthur "genius" award for his work identifying the man-made causes of global warming, and who had become an especially harsh critic. Santer said he believes that Christy is more interested in proving his satellite data is correct than getting to the bottom of what is happening with the climate.
"Most of the scientists I've met in my career have genuine interest in advancing scientific understanding," Santer said in an email. "In my opinion, Prof. John Christy does not."
Santer was harsher in private, as became clear in 2009 when a hacker broke into a server in the United Kingdom, retrieved thousands of emails exchanged among climate scientists and posted them on the Internet.
"John Christy has made a scientific career out of being wrong," Santer wrote to colleagues in a 2008 email. "He's not even a third-rate scientist."
To Christy, the so-called "Climategate" emails provided evidence of his unfair treatment.
To this day, Christy keeps taped to his office door a reminder of the disparagement—a crude photo illustration that one of the climate scientists circulated, depicting Christy along with other prominent critics of climate science, trapped on a disappearing iceberg at the North Pole.
A caption on the iceberg illustration has the chorus of skeptics saying, "Global warming is a hoax," while Christy, kneeling at the water's edge, chimes in with "Satellite readings show continued cooling," and a pensive polar bear stands on its hind legs, looking on.
"They even started calling us deniers, which has a Holocaust reference to it, and it's just really offensive and derogatory, denigrating," Christy said. "We don't deny climate change. We don't deny that there's extra CO2 in the atmosphere. We don't deny that it has an effect on climate. We are trying to find out how much."
Christy, Spencer and a few other stalwart contrarians remain apart from the rest of the scientific community, where a consensus on the danger of anthropogenic greenhouse gas emissions has grown, a result not only of the temperature data, but of evidence like the retreat of sea ice, the loss of glaciers, the amount of snow cover, ocean heat content, the change in the chemistry of oceans, the paleoclimate record, the migration of species, the stress on ecosystems and other lines of evidence.
"I don't think it is tenable anymore for him to argue that there is any inconsistency between the satellite data and all of the other datasets that demonstrate the warming of the surface and atmosphere," said Mann, the Penn State climate researcher. "There just isn't."
However, when the Trump administration began to implement its agenda to dismantle federal policy on climate change, Christy's work gained new prominence and a new source of support.
In Trump's Washington, Christy's Star Rose
Before the 2016 election, Christy lamented the lack of federal funding for his work.
"Contrarian proposals, such as one I might write, that want to, say, look rigorously and test climate models against reality or to test various ideas about how natural variability causes these changes, are rarely, if ever, funded," he said at a December 2015 Congressional hearing.
Spencer had expressed similar frustration on his blog: "We scientists who still believe that climate change can also be naturally forced have been virtually cut out of funding," he wrote in 2013.
But in September 2018, Trump's Department of Energy announced that Christy and Spencer's team had been selected for a three-year, $1.5 million grant to develop a new method of determining how the Earth's climate is responding to greenhouse gases. In a press release, the UAH team said they thought their approach would be "more accurate than current methods."
The research will use Christy's satellite measurements, which generally record cooler temperatures than those recorded by other groups studying the same satellite readings. Christy said he would combine those with measured snowfall amounts in three Pacific coast states to find how much human-generated carbon dioxide emissions have impacted the climate.
In an interview, Christy said the results of his research could be "part of the evidence that can be used, say in court, to say the Obama administration's actions and regulations on climate change were based upon inferior information."
In 2019, the Trump administration gave Christy an even greater show of support, when he was selected to serve on EPA's Science Advisory Board, a 45-member panel of outside scientists who are meant to provide input on major agency initiatives. The EPA often points to the advice of its Science Advisory Board when it writes new regulations, in order to counter the inevitable legal challenges the agency faces over its major actions.
Christy's appointment was part of a dramatic overhaul of the advisory board under Trump's two EPA administrators, Scott Pruitt and Andrew Wheeler. Pruitt created an unusually large number of openings on the board by instituting a new rule, barring scientists who received EPA grants from serving as board members. (Because Christy's grant came from the Department of Energy, not EPA, he was not barred by the conflicts policy.)
The EPA announced in August that EPA grant recipients would no longer be barred from the board, after two federal judges ruled that the policy was illegal. Christy's three-year term continues through 2022.
Earlier this year, Christy provided input to the Science Advisory Board as it considered the Trump rollback of fuel economy standards and the withdrawal of California's authority to set its own standard, which was tougher than the federal regulation. The weakening of passenger vehicle standards is expected to have the largest greenhouse gas impact of any of Trump's anti-climate moves, resulting in the release of more than one gigaton of additional carbon into the Earth's atmosphere by 2035—the equivalent of one current year's worth of transportation emissions from the European Union.
But in a memo to the advisory board, Christy said whatever rule the Administration adopted, it would have no measurable impact on the climate.
"Consequently," he wrote, "it seems to me, one should take the pathway that leads to healthy economic development, especially for the more financially-constrained citizens of our country."
The board included Christy's perspective in a footnote: "Some members of the Board noted that the direct impact on global temperatures would be very small," they said.
Christy's advice may prove important because the administration, after finalizing its rollback of fuel economy standards in March, is now in federal court defending the move against lawsuits by California and other states, as well as environmental groups. Part of the Trump administration's legal argument is that the California standards have no impact. "They do not meaningfully reduce the overall U.S. contribution of greenhouse-gas emissions to the world inventory of such emissions," the Trump administration said in its brief in September.
Gretchen Goldman, research director of the Union of Concerned Scientists' Center for Science and Democracy, said that the appointment and funding that the Trump administration gave Christy will have an impact long beyond Trump's term in office. "Historically, the scientists on these advisory committees were not chosen for their policy views," she said. "But the Trump administration has treated these like political positions, putting in people who were friendlier to their agenda. And by elevating people like Dr. Christy, they hope to get more of an appearance of scientific backing for their policy positions, even when those positions don't enjoy broad support from the scientific community."
At Home in Alabama
Christy continues to have plenty on his plate in Huntsville, where he is director of the university's Earth Systems Science Center and interim dean of the College of Sciences, with its more than 1,700 undergraduate and graduate students.
Since 2000, Christy has also served as Alabama's state climatologist, an office with $850,000 a year of state funding, through the University of Alabama System budget. (For comparison, the entire Alabama Department of Environmental Management, which polices industrial pollution in Alabama, received only $575,000 in direct state funding in 2019.)
In addition to working to improve weather monitoring capabilities in the state, and keeping records of climate conditions in Alabama, some dating back to the 1800s, Christy said he also plays a role in the state's economic development. Although the details of that work are confidential, he said, he was able to allay the fears of a manufacturer who was considering expanding by assuring the company that tornado risk was low.
Christy is also still active in his church, First Baptist in Huntsville, occasionally leading discussion groups about the intersection of science and religion. Huntsville, known as the Rocket City because of the NASA center, has a huge, per capita quotient of engineers and scientists, even in its Southern Baptist Bible study groups.
Christy met his second wife in the church choir, after Babs—a locally beloved figure in her own right—died of cancer in 2014.
"I know that John is a man of faith and that his faith informs his view that we must do all we can to help our fellow human beings," Mann said. "The best way he could do that is by being more objective in his framing of climate change risk."
Christy is undeterred. He has run 18, 31-mile marathons, including one that became 34 miles after he got lost on a mountainous course, and he has a shelf full of trophies.
It's not in his nature to give up, he says.
"I finished every [race] I started, so that's kind of a little bit of indication maybe when I get a bee in my bonnet about the accuracy of what climate science is doing," Christy said, "I might not let go."