There was a time when Angelica Lim, a Canadian robotics professor, travelled 20 times a year by plane, often to scientific conferences overseas. Then she took a test to calculate her carbon footprint.

The results were shocking.

"I realized that my carbon footprint was something like 20 times over what our goal should be," Lim, an assistant professor and artificial intelligence scientist at Simon Fraser University, told CTV News.

The discovery was a wake-up call. These days, Lim flies just once or twice a year. She's now part of a growing movement of scientists and researchers who are finding other ways to connect with their international peers without contributing to air-travel pollution.

The no-fly movement is already gaining traction in Sweden, where the concept of flight shame is so mainstream that it already has its own word: flygskam (pronounced "fleeg-skahm.")

Instead, many climate-conscious Swedes are getting behind the idea of tagskryt, which translates to "train brag." On Instagram, more and more travellers are using the word to boast about the low-carbon travel option.

This week, the movement was given a major publicity boost after climate activist Greta Thunberg travelled from the U.K. to New York City by sailboat to raise awareness about zero-emissions forms of travel.

For scientists and academics, flying overseas to attend conferences and meet face-to-face with other researchers is common. But the environmental toll is hard to ignore.

A round-trip flight from London to New York City releases about 986 kg of CO2 per passenger, according to Atmosfair, a German nonprofit organization. That's more than the average citizen of countries such as Burundi and Paraguay releases in an entire year.

Estimates suggest that aviation is responsible for two per cent of the world's annual emissions. That number is expected to skyrocket in the near future. According to the International Civil Aviation Organization, air travel emissions will grow between 300 and 700 per cent from 2005 to 2050.

Those numbers set off alarm bells for Peter Kalmus, a California-based climate scientist. So he started No Fly Climate Sci, a group that encourages both academics and members of the public to ditch air travel.

He says the movement is about putting your money where your mouth is.

"As earth scientists, for example, we can tell the public that this is an urgent issue, but actions speak louder than words," he said.

Universities are beginning to follow suit. Concordia University's geography department adopted a "flying less" policy earlier this year, which encourages researchers to hold "travel-free" meetings and opt for ground transportation for trips 12 hours or less.

Ottawa-based environmental scientist Richard Fernandes recently made the choice to quit air travel altogether. For him, the turning point was when he realized that a quarter of his carbon emissions came from flying.

The decision wasn't easy.

"I have to make choices, and my choice is personally -- for my own personal travel -- I don't fly anymore, I have relatives overseas and i would like to visit them, but I don't do it," he said.

Instead, Fernandes has turned to online forms of communication to keep in touch with the larger research community.

"A year ago I told my colleagues overseas: 'This is the last time I am going to see you personally, unless it's a critical need,'" he said.

For Lim, tools like Skype and FaceTime are easy ways to stay in touch. Other solutions include Beam, a mobile video conferencing technology; Double 3, a self-driving videoconferencing robot; and virtual reality conferencing using 3D technology.

Some scientists argue that face-to-face meetings are important because they foster personal relationships and help create more lasting connections. Those who've limited their air travel say they're open to flying when required but the key is to put a limit on more frivolous meetings.

Fernandes said that, so far, e-meetings are more than sufficient for him, even if they sometimes require a bit more work.

"It means a little bit more effort and quality control. It's means effort in planning things," he said. "Maybe that's the way in the future I have to do it to reduce my personal greenhouse gas emissions."