Jirapatch Iamkate / EyeEm via Getty Images Every round trip from New York City to London costs the Arctic 30 square feet in lost ice.

Customs and Border anxiety, the boredom of endless lines, and jet lag: flying sucks. Add guilt over carbon emissions and it becomes harder to justify why we still do it. The aviation industry is currently responsible for about 2 percent of global greenhouse gas emissions. This figure is set to grow as air travel becomes increasingly popular. Airlines transported 4.3 billion passengers worldwide last year, an increase of 38 million over the year before. For every round-trip flight from New York City to London, which releases a ton of carbon dioxide into the atmosphere, 30 square feet of Arctic ice is lost. Efforts to reduce the effects of aviation are moving at a very slow pace. Emissions-cutting innovation is still many years, maybe decades, from implementation. Electric and solar-powered airliners are reportedly in development at Wright Electric and Airbus among others, but battery technology still lags behind jet fuel. The startling effects of aviation are why a number of people are choosing to quit, or hugely restrict, flying. While “staying grounded,” as activists call it, might not make the biggest difference to your carbon footprint ― a study last summer found that cutting meat, eggs and dairy was the best thing people can do for the planet ― it can still make a huge difference. One of the more noteworthy non-flyers in the news lately is climate activist Greta Thunberg. The 16-year-old took a 32-hour train from her home in Sweden to Switzerland to deliver her speech at Davos. She hopes to join a bigger movement for changes to the aviation industry ― and wants her behavior to make a statement. “I’ve decided to stop flying because I want to practice as I preach, to create opinion and to lower my own emissions,” she told HuffPost by email. “One person who stops flying will not make a difference. But if a large number of people do then it will. It sends a message that we are in a crisis and have to change our behaviour.” Peter Kalmus, an author and climate scientist living in Altadena, California, stopped flying in 2012 after clocking 50,000 miles in 2010. He set up the website No Fly Climate Sci for others who are doing similar things. His wife and their two kids, 10 and 12, agreed to swap plane journeys for car journeys. He says he feels frustrated by arguments that pit personal choices against wider movements for change. “The whole ‘individual versus collective’ thing is a false dichotomy,” he said. “We have to stop having this fruitless debate because action at any level leads to more action at every level. All these levels of action ― community, individual, national, international ― they’re all feeding back on each other.”

Courtesy of Peter Kalmus Peter Kalmus, an author and climate scientist, quit flying seven years ago.

Zoe Hatch, who lives in Maidenhead in the U.K., stopped flying in 2015 after reading up on climate change and learning about climate feedback loops. Her husband and their two children, 11 and 15, joined her in a family decision to switch to slow travel. Hatch hasn’t found it inconvenient or expensive, she says. She uses apps and sales alerts to find affordable train tickets. Being connected to continental Europe by the Eurostar train makes it relatively easy to travel abroad without needing to fly. “I wanted to introduce my kids to just being able to pick up a bag and travel,” she said. “When you’re flying it’s like you’re beamed into a different location, whereas when you go on a train journey, you can feel the transition.” Dave Ogden from Edinburgh, Scotland, managed to avoid planes for four years after reading up on climate change when the Paris agreement was in the news in 2015. He was inspired by an article by climate change professor Kevin Anderson. “It was targeted at climate researchers but it resonated with me and changed the way I was thinking about burning carbon,” he said. “I started to learn about the [United Nations’] carbon budgets and something clicked in my mind.” His commitment is not rigid, however, much as the emphasis on more planet-friendly diets has led more people to follow a “flexitarian” diet, rather than becoming vegan. Ogden has managed to travel to France and Germany by train but, after doing a doctorate in renewables, hopes to travel to the U.S. for work: “You have to be realistic really. I mean, we emit carbon all the time. It’s just about being more mindful of how much you’re emitting.” Kim Cobb, a professor of earth and atmospheric sciences at the Georgia Institute of Technology, was also shocked by the stats. In 2017 she calculated that 85 percent of her carbon footprint came from flying. She used to fly 120,000 miles and has since cut that down by three-quarters. The toughest part for Cobb is finding a way to see her husband’s family in Italy. “This year, I am reserving the biggest chunk of my flight emissions for this one trip. This will have to go from being a once every year or two trip to a once every decade or so trip. But we’ll see what my husband thinks. He has not curtailed his flying yet, and that is fine with me,” she said.

Courtesy of Kim Cobb Kim Cobb, a professor of earth and atmospheric sciences, has hugely reduced her flying.