A group of Earth scientists takes the train instead of a plane to protest climate change. But can the rest of us climb aboard?

In October in Boulder, a group of University of Colorado Boulder Earth scientists sat on a lawn next to a library and talked about something they will soon do to protest climate change. Today, they boarded an Amtrak train at Denver Union Station and took it to the San Francisco Bay Area, where they will attend the largest scientific meeting of Earth scientists in the world— that of the American Geophysical Union. 

By train, the trip can take anywhere between the advertised 31 hours and forever to complete, while a plane can make the same trip in just a few hours from gate to gate. So, why not fly? 

Because, the group explained, flying is one of the most fossil fuel-intensive things people do, and they want to set an example. 

Climate change-related crises like floods and wildfires are emerging left and right around the planet, and as the kinds of scientists who revealed human-driven climate change to the world in the first place, the group thinks that they stand to lose their credibility if they keep not heeding their own field’s forecasts.

“I do think there’s a very weird thing about being like ‘climate apocalypse!’ and then getting on a plane,” said Mylène Jacquemart, a Ph.D. student in geology who co-organized the trip.

“It’s hypocritical,” said Joep van Dijk, a climate scientist who works as a postdoctoral researcher at the Institute of Arctic and Alpine Research at CU Boulder and planned the trip with Jacquemart. 

“How are you going to convince anyone that this is a serious issue if you don’t show it?” 

In January, van Dijk moved from the Netherlands to Colorado to start his new job. He made the trip without stepping on a plane, just as climate activist Greta Thunberg did in August. It took him roughly three months. He crossed the Atlantic on a catamaran, and once he got to the United States, he decided to give up flying completely. 

As it happens, van Dijk, Jacquemart and their group of seven others are not alone. Each year since 2017, scientists from the Scripps Institution of Oceanography at the University of California, San Diego have been taking Amtrak from San Diego to the get to the same meeting. The University of California, Los Angeles, now charges its departments on a per-flight basis, and researchers at universities in Europe, like ETH Zurich in Switzerland, are monitoring their flying habits.

In 2017, climate scientist Peter Kalmus, who hasn’t flown since 2012, founded the group No Fly Climate Sci as a call to Earth scientists and others to curb their flying. 

“The public doesn’t realize how permanent the stuff we’re doing now is. This is a global-scale permanent change to ocean currents and ice sheets and sea level that we’re not going to be able to reverse,” Kalmus said. “I equate those emissions to my kids’ futures, and it feels like I’m stealing from it.”

Between a rock and a hard place

Quitting flying completely is a hard ask for scientists who study the planet for a living, and, for them, it can be hard to know where to draw the line—when it comes to making potentially-groundbreaking discoveries, and also when just visiting family.

Jacquemart, for her research last summer, took the train to Seattle, got on a plane to Alaska, and then took a helicopter to remote field sites. 

She made the journey so she can figure out how glaciers are melting in our warming world, because she wants to know how those melting glaciers can pose a hazard to those people who live near them. Melting glaciers, she explained, can collapse abruptly and race downslope as swarms of rock and ice. 

For his research, before he ever stepped on a catamaran, van Dijk crisscrossed the planet, flying to Argentina, California, Hungary and Kyrgyzstan. He collected samples of ancient soils so that he could study a time when, about 56 million years ago, global warming unfurled in a way similar to today’s warming. 

That ancient warming is what experts think the world could look like by 2100: no ice caps, acid oceans, among other things. 

“It scared the heck out of me,” said van Dijk, who now thinks all Earth scientists need to cut down their flying, and that science funding agencies like the National Science Foundation need to start considering the carbon footprint of research projects before awarding any money.

Not everyone, though, is on board with the call to take the train. One hydrologist, who asked to remain anonymous, said that taking something like the train in the U.S. for long-distance work trips is out of the question. Why? Because Amtrak, especially in the West, can be unreliable.

In August, on a trip from Denver to the Bay Area, the train was about four hours late getting to Denver Union Station. Right after leaving Denver, the train stopped for over an hour to wait for a stalled freight train to move. For someone traveling for work, or for someone juggling both work and also family commitments, like the hydrologist, such a delay can derail their plans. 

“I think that there are reasons we fly. Some reasons are better than others,” said Corrine Le Quéré, a climate scientist at the University of East Anglia in the United Kingdom. 

Lequéré was the director of the Tyndall Center for Climate Change Research for eight years, and when she assumed her leadership role, her colleagues criticized her for all the flying she was doing. In response, she and the center developed a strategy for reducing individual emissions in a way that reflects the emission reduction goals of their home country. 

For Lequéré, this meant an immediate 50 percent reduction in her flying, with an aim of net zero emissions by 2050, along with increased use of alternatives like videoconferencing. 

“We have an image. Whether we like it or not, we are looked at as a community. What we do matters in a way that doesn’t apply to all scientists in the world,” Lequéré said. “People did good science before aviation.”

All aboard?

Earth scientists form a microscopic part of the overall population, and changing the way all people get around is not as straightforward as buying a ticket for the next Amtrak train—particularly since Amtrak emissions can also be relatively high depending on the journey.

According to the United Nations’ Intergovernmental Panel on Climate Change, global warming needs to stay below 1.5 degrees Celsius to keep climate catastrophes from amplifying. This means humanity needs to cut greenhouse gas emissions by 45 percent from 2010 levels by 2030. 

The Green New Deal, introduced in the House of Representatives in February, calls for an overhaul of transportation in the U.S. to help reach this goal. Yet, details on what such an overhaul would take are scarce. 

“If you stop flying all airplanes, it wouldn’t really matter for climate change,” said Andrew Gettelman, a climate scientist at the National Center for Atmospheric Research in Boulder, Colorado. 

Commercial jet-powered aviation emitted about 918 million metric tons of carbon dioxide into the air in 2018, and that only accounts for about 2.4 percent of all greenhouse gas emissions. 

Those emissions, however, could grow with time: according to the United Nations’ International Civil Aviation Organization, aviation greenhouse gas emissions stand to balloon alongside increasing demand and, by 2050, could triple. 

“Without a fundamental change in the way we as a society conceptualize air transportation, we are headed in that direction,” said Megan Ryerson, an aviation transportation expert of the University of Pennsylvania. 

The jet-powered aviation industry burns over 90 billion gallons of jet fuel each year, and the U.S. consumes about 27 billion of those gallons. Renewable jet fuels do exist, and one, made by World Energy in Paramount, California from fats, oils and greases, can reduce net carbon dioxide emissions by more than 70% compared to typical petroleum-based fuels. 

This fuel’s use, according to Steve Csonka, who is the executive director of the Commercial Aviation Alternative Fuels Initiative, could help the aviation industry reach its self-assigned goal of 50 percent net reduction in greenhouse gas emissions by 2050. 

Right now, though, there are three facilities in the world that produce such fuels, and what it would take for widespread adoption of renewable jet fuels to happen is hard to define. 

“It’s a question of at what point society decides we need to start doing more,” Csonka said. “My divination skills are no better than yours.”

Meanwhile, according to transportation expert Marlon Boarnet of the University of Southern California, flying does not need to be the sector where a transportation overhaul starts. 

Half of all trips in the U.S. are three miles or shorter, and as driving accounts for the largest source of greenhouse gas emissions in the U.S., ground transportation is one area that stands to make the greatest immediate strides when it comes to emissions reductions.

For one thing, “fuel prices are too low,” Boarnet said. Americans pay about half of what Europeans do at the pump; in the U.S., in 2018, gasoline was about $2.90 per gallon on average, while in France gasoline was about $6.58 per gallon. 

Raising fuel prices, alongside other policies like New York City’s new congestion pricing policy, could help curb congestion, curb emissions, and also generate funds and demand for alternative forms of transportation.

Data from the American Public Transportation Association reveals that Americans’ use of public transportation declined by about two percent in 2018, and efforts to build high-speed rail in the U.S. are stalling, but alternatives to driving, according to Dr. Boarnet, are making impacts in cities around the country. 

In Los Angeles, he led a research team that found that in households within a half-mile radius of light-rale lines that opened in 2012, driving rates dropped by 40 percent. This result surprised the team, especially since it happened in a city long associated with one mode of transportation: the car. 

“I think that’s the lesson: people really will change,” Boarnet said. “Which is very good news.” 

For van Dijk, he thinks his change of travel style after his transatlantic voyage has benefited his science, because it forced him to slow down and consider things. 

“At the end of the day, you have to have a certain sanity to be able to conduct productive research,” he said. “I’m convinced that traveling slow is actually traveling fast.”