" Clouds are gathering over the campus of the University of Memphis as I arrive at the office of Dorian J. Burnette, professor of meteorology, climatology, and extreme weather. The Wichita, Kansas, native grew up in the heart of tornado alley. "That's how I got into it, running from tornados," he says. "Now, I take students, and I run toward tornados."
Burnette's the kind of person who sweats the details — you have to be if you want to be a successful scientist. When he talks about combing through 150-year-old documents for historical weather data, his enthusiasm is infectious. It helps to be passionate when your job involves looking deeply into the greatest existential threat human civilization has ever faced.
"Anthropogenic climate change — global warming — really shows itself from 1950 to the present," he says.
Since the Industrial Revolution, the burning of coal, natural gas, and oil for energy generation and transportation has been subtly changing the chemistry of our atmosphere. The carbon dioxide released from tailpipes and smokestacks absorbs heat more efficiently than does the nitrogen and oxygen that makes up most of our atmosphere. As we add more CO2 to the air, it gets hotter.
Burnett's specialty is dendroclimatology. He spends a lot of time examining tree rings under a microscope. "We see a pattern of wide and narrow rings. The wide ring is when the tree liked the environment. A thin ring — or maybe no ring at all — is when the tree hated the environment and was really super stressed. Those matching patterns of wide and narrow rings are consistent over large areas."
- David Kabelik
- Dr. Burnette coring a bristlecone pine tree in Colorado for a tree-ring project.
Examine enough trees over a large enough area, and you can reconstruct the history of the climate. "Here is the Southeast, and we can get back several hundred years to potentially a thousand years, depending on what part of the Southeast you're talking about. There are some kinds of trees that can go back 2,000 years in the Southwest."
The evidence for man-made climate change, Burnette says, is clear, and not only in the tree rings. He sees it in daily weather observations made by Army officers dating back to 1821, in the National Weather Service records from the 20th century, and in NASA satellite observations from the 1970s.
"Each one of these separate metrics have their own strengths and weaknesses, and they're not necessarily the same. And yet we get a similar answer when we carefully evaluate all of the data. But the most compelling evidence that the Earth is undergoing change is to just observe the natural world itself. Most of the glaciers are retreating. There are non-migratory species who are moving ... 90 percent of physical and biological systems are responding in a direction that is associated with warming."
TENNESSEE IN 2099
Across town, at Rhodes College, Sarah Boyle, chair of the Environmental Studies and Sciences program, is grading projects from students in her Geographic Information Systems (GIS) class. Dr. Boyle is a biologist; her speciality is deforestation. "When I was younger, I was primarily interested in primates — monkeys and apes. When I was in college, I pursued my interest in that area. I lived in the Amazon for a couple of years and tracked monkeys through areas that had been deforested and through areas that were not as impacted by humans to see what the differences were in tree species composition, which primates were there, which ones had gone locally extinct, which ones remained. How did their behavior and biology change?"
Like all plants, trees breathe in carbon dioxide and breathe out oxygen. To absorb the excess CO2 we're releasing into the atmosphere, we need more trees. Instead, humans are cutting down forests at an alarming rate. "Deforestation reduces the available carbon sinks," she says. "Sometimes people burn [the forests], which releases a massive amount of carbon dioxide."
The students in Boyle's GIS class come from all majors, not just STEM fields. "Just recently, they were looking at different climate predictions for the state of Tennessee in terms of, under different scenarios, what would the temperature and precipitation look like in 2099?"
Giovanni Boles is one of Boyle's students. "I was born and raised in the Netherlands, so climate change has always been a topic of discussion," he says. "The Netherlands has always been threatened by the rising sea levels, especially considering that a third of the country is below sea level. Climate change has to be on the agenda for everybody, regardless of their location."
Boles and the others fed a trove of historical climate data into a computer model that used realistic estimates from the Intergovernmental Panel on Climate Change (IPCC) about future population and economic growth, land use, technological advancement, and, most crucially, oil and gas consumption. "They went through and modeled it out in all the areas of Tennessee to see overall what the changes would be. Based on this model, you do have a rise in temperature and a rise in precipitation. But it's not uniform across the state. ... They could see immediately that the southwestern areas of the state are quite different than the eastern part of the state."
- Dr. Sarah Boyle in the Amazon
Boles' results indicated an almost seven-degree-Fahrenheit rise in average temperature, both minimum and maximum over the course of the century. "Looking at the gradient, some of them were shocked to see the huge range," says Boyle.
Burnette says this pattern is consistent with predictions made by climate scientists for decades. "We have high uncertainty with certain aspects of anthropogenic climate change, but there are things that are really robust in the literature. Depending on what part of the globe you're in, your average annual total rainfall may not change too much, but you're liable to get more rainfall in heavier amounts, with longer, dryer spells in between. The fact that heat waves will become worse, that keeps coming out in the literature as well. Winters are not going to be as bad, because winters are warming faster than summers are."
So it will get warmer. So what? Maybe more rain and shorter winters will extend the growing season and give us more crops. Not so fast, says Burnette. "You put yourself in danger of a 'false spring.' We saw that this year. It gets warm really, really early — like January and February — and refuses to cool back down. Then, all of a sudden, in March, you get a late-season shot of cold air. That's damaging to the plants that are starting to bloom. You can see it on the trees right outside. The leaves are kind of sickly looking in spots. That's a function of the hard freeze we had after the trees had already started developing their leaves."
The chaotic climate will stress food crops. "The tropics are going to get hit the hardest, right away," says Burnette. "If you warm up the temperature just a little bit, it will make it unsuitable for crops. There will have to be a shifting of the growing belts down there. Up here, there will be a little more room for warming. That's where that 1.5- to 2-degree shift starts popping out. Once you get above that, you start seeing declines in yield. That implies that, if we warm up the planet a little bit, we can initially see some increases in yields in certain crops because of a longer growing season. But once we pass a certain key threshold, you start to lose the gains. Then if you warm up a little bit more, you have to shift. Do we want to take some crops that are relevant to the state budget and give them to another state? That's where the rubber meets the road in terms of politics."
The scientific consensus is that we need to prevent global average temperatures from rising more than 2.0 degrees C on average (about 3.6 degrees F). "The reason we chop it off right there is because we start seeing some issues with the planet itself, the biosphere of the planet, once you reach that threshold."
Beyond the 2-degree threshold, the climate models lose coherence. Burnette says there is potential for disaster of unimaginable scale. "The Younger Dryas event has been studied significantly. It happened about 12,000 years ago. There was an abrupt cooling phase and then an abrupt warming phase at its start and end points. Some of the indications suggest that you can go from general warming conditions back to full glacial conditions in as little as 10 to 50 years. ... There are tipping points, but you can't really see one until, oops, you've moved across it already. Now, it's too late to deal with it."
DECEPTION + DENIAL
"I find the political aspect really interesting," says Boyle. "In cities where people have been really impacted by these extreme climate effects and changes, the general populace says, yes, this is an issue. Insurance companies think this is an issue. But at the [political] party level, it's this 'yes or no' fight, which is really unfortunate."
The landmark Paris Agreement of 2015 set out goals and methods for each country to meet the crucial 2-degree target. But the 2016 election of climate-change denier President Donald Trump has thrown that process into chaos and uncertainty.
"Trump's belief that climate change is a Chinese hoax should alarm everyone and epitomizes his proclivity for baseless conspiracy theory," says Scott Banbury, Conservation Program Director for the Tennessee Sierra Club. "In fact, China is making enormous investments in clean energy, and Trump's threatened abandonment of the Paris Climate Accords will result in the U.S. being less competitive in the future."
It's not just Trump. In March, Tennessee Senator Lamar Alexander went on a 12-minute tirade in the Senate, railing against TVA's plans to buy wind power — which does not add any carbon dioxide to the atmosphere — from Clean Line Energy Partners, operators of a wind farm in Oklahoma. He claimed that the deal would impose an unnecessary $1 billion cost on Tennesseans over a 30-year period. "TVA should not agree to buy more wind power, which is comparatively unreliable and expensive," he said.
Banbury and the Sierra Club disagree. "Senator Alexander's opinions on wind power are based on very outdated information. Clean Line is offering fixed, long-term rates that are cheaper than the current cost of generating electricity from coal, will undoubtedly be cheaper than natural gas in the near future, and free of the financial and environmental risks of nuclear."
Denying the reality of climate change has become an article of faith among most Republicans. Fossil fuel industries have thrown big money into sowing doubt among the conservative flock. Burnette says a favorite Fox News tactic is to exploit scientists' unwillingness to speak in absolutes. "You listen to a scientist, and they're going to caveat themselves constantly. We allow for these little probabilistic things that could technically happen."
But on TV news programs, "They'll bring on a climate scientist, and then they'll bring on another person who may be a Ph.D., but he's not necessarily super credentialed, and if you look at his publication record, he hasn't contributed to the peer-reviewed literature at all. They bring these two head to head, and the audience sees one scientist arguing against another and think there's discrepancy between the scientists." This creates the impression that 50 percent of scientists think one way, and 50 percent of the scientists think another way. "It's somewhere in the 90 percent range that think anthropogenic climate change is real, it's a threat, and it's us," says Burnette.
"I was shocked. I didn't see it coming," says Nour Hantouli, of the election of Donald Trump. "I was hoping that Hillary was going to get into office so we could talk about how we needed to go even farther than that. Now, we're starting from absolute ground zero with Trump."
Hantouli is one of the founders of the Memphis Feminist Collective, a three-year-old organization active in community organization before and after the election. "Activism in Memphis is getting a lot more traction. I've never seen anything like it. There was the Women's March, the Immigration March, they had thousands of people. We haven't seen that in decades."
Hantouli is one of the Memphis organizers of the March for Science, a national movement to push back against Trump Republicans' proposed gutting of government science research. First on the chopping block are the EPA and NASA's climate science programs.
"Our goal is to highlight the national goal of bringing science to the public, by reaching out and bringing them in," says Hantouli. "We want to let folks know why these intersections are important and why we have to unite against these policy changes and the toxic cultural climate that's going on."
Scientists prize objectivity above all else. Politicization of science is a major taboo, and for some, that even extends to taking political action in self-defense. "You say you're not into politics, but politics is into you," says Hantouli.
The initial March for Science organization was done by a coalition between scientists and academics, who had little experience in the field of direct political action, and experienced social justice organizations such as Hantouli's Memphis Feminist Collective. Tensions mounted over methods and priorities, and the internal conflict came to a head with a proposal to rally in Health Sciences Park adjacent to the University of Tennessee medical campus. Unfortunately, that is also the site of the grave and statue of Ku Klux Klan founder Nathan Bedford Forrest. The debate split the group, and as a result, there will be two separate March for Science demonstrations in Memphis on April 22nd. One, a march from Gaston Park to LeMoyne Owen College, and the other a rally at Civic Center Plaza.
"If your life has been touched by science, if you want to meet Memphis STEM professionals and educators, or if you want to discover and contribute to the inclusivity of the Memphis STEM community, this is a first of its kind event in our lifetime to make that connection," says Rally for Science Memphis spokesman Colin Kietzman.
"The problems we've been seeing here in Memphis are not unfamiliar to everyone else. The scientific community and their relationship to the public has been an issue. That's something we have to work on," Hantouli says.
KEEPING HOPE FOR THE FUTURE
"People ask me, 'How can you study what you study without being horribly depressed?' I think as you work toward the problems, you have to have some optimism that the work you're doing will provide some positive changes in the future," says Boyle. "I see that in the students. They know how dire the issues are, but I think they have that optimism to work toward a goal for a better future."
"We've had some good news of late," says Burnette. "Emissions are not as high. That's good. That's buying us a little bit more time. That's the encouraging thing. I try to look at it from an optimistic point of view. It's certainly not too late, and that's not just optimism talking. But the problem is, the longer we wait, the correction is going to have to be much more draconian to fix the problem. That's the reason why I wish a certain group would stop arguing about the science and start talking about policy."