Why some climate scientists are saying no to flying

In 2016, two seemingly unrelated events conspired to make Kim Cobb confront her personal carbon footprint. First, a massive El Niño event hit the coral reef researcher’s 22-year study site, warming the ocean to record levels and killing 85% of the reefs. During her first scuba dive afterward, “I was crying in my mask,” says Cobb, a professor at the Georgia Institute of Technology in Atlanta. It’s one thing to read papers about coral bleaching, but when it happens to a place where “you know every dive like the back of your hand, it’s something different.” Then, a few months later, her hope for government action to tackle climate change was extinguished when Donald Trump was elected U.S. president.

So, she started to do a rigorous accounting of the carbon that she’s responsible for emitting, finding that air travel accounted for a whopping 85% of her carbon footprint in 2017. She’d flown roughly 200,000 kilometers that year, mostly to conferences. She vowed that 2018 would be different. “Flying is a luxury and a privilege that must be reserved for a fraction of the events that we use it for right now,” she argues.

Cobb is one of a small but growing minority of academics who are cutting back on their air travel because of climate change. Traveling to conferences, lectures, workshops, and the like—frequently by plane—is often viewed as crucial for scientists to exchange information and build community. But Cobb and others are questioning that perspective—pushing conferences to provide more opportunities to participate remotely and changing their personal behavior to do their part in confronting the climate change crisis. On a website called No Fly Climate Sci, for example, roughly 200 academics—many of them climate scientists—have pledged to fly as little as possible since the effort started in 2017.

Cobb, for her part, started to ask conference and institutional representatives who invited her to speak whether she could do so remotely; about three-quarters of the time, they agreed. When the answer was no, she declined the invitation. That approach brought Cobb’s 2018 air travel down by 75%, and she plans to continue the practice. “It has been incredibly rewarding,” she says—“a really positive change.”

Peter Kalmus, a climate scientist at the University of California, Los Angeles, who started No Fly Climate Sci, acknowledges that “most of our colleagues think that we’re a little odd for flying less.” He hopes the site helps like-minded scientists “feel like we’re a little bit of a community.” Kalmus began to limit his air travel as a postdoc in 2011 after he switched from studying astrophysics to studying the Earth’s atmosphere and calculated that three-quarters of his carbon footprint in 2010 came from flying.

In 2012, he made a more dramatic change after flying to Europe to meet with collaborators. On the way there, “I had this strong feeling that I didn’t belong on the plane, but the doors were already shut.” He has opted for ground transportation ever since. He didn’t vow never to get on a plane, but since 2012, he has not felt he needed to. Instead, Kalmus often coordinates conference attendance with an annual train trip from California to Illinois to visit family. Many of his meetings and collaborators are also in California, which lessens his need to fly.

As Kalmus sees it, it’s not just about reducing his own footprint; it’s also about setting an example. “It’s inevitable that the public looks to us [climate scientists] to gauge the urgency of the situation,” he says. If you’re “walking the talk” then the public will see you as a more trusted messenger of the urgency of climate change.

Others disagree with that approach. Cobb says that senior scientists have told her the “flying less movement” is harmful because it distracts from the message that global emissions can only be reined in through collective government action. Still others support the movement but have no choice but to take planes for work. Chandni Singh, a climate adaptation researcher at the Indian Institute for Human Settlements in Bengaluru, added her name to the No Fly Climate Sci website after noticing that most of the profiles were written by European and U.S. academics. In Europe, she often hears colleagues say “‘I came by train’ or ‘I cycled from France to Germany’ or something like that.” But that’s just not possible as a researcher in the developing world who needs to attend meetings in Europe and North America, she says.

Reducing air travel can also be a disproportionate sacrifice for junior scientists, who benefit from networking and sharing their work at conferences. Nadir Jeevanjee, a postdoctoral researcher studying atmospheric physics at Princeton University, recently signed up on No Fly Climate Sci and has started to limit his air travel when possible. He’ll be taking an all-day train trip to a conference later this year and recently inquired about giving a virtual talk for a meeting in the United Kingdom. But he says some air travel may be unavoidable. “If you’re an early-career researcher and you’re traveling very little, I think it’s hard to build awareness of your work,” he says. “You have to be standing around at the coffee break to chat, and you can’t do that if you’re not there.”

Cobb agrees. Early-career researchers “should have unfettered … access to flying to build their careers just as I did,” she says. It’s the senior, more established scientists—such as herself—who should curtail air travel, she says. That could make the biggest dent in the problem, too: A study published online last month calculated that, at the University of British Columbia in Vancouver, Canada, full professors are responsible for three times as many flight-related emissions as grad students and postdocs.