A climate-conscious man travelled from England to China without getting on a plane.
Roger Tyers instead took a month to journey the 13,500 miles from Southampton to the Far East.
The 37-year-old's epic odyssey included 24 trains across nine countries and cost him more than £2,000 - almost triple the cost of a return flight.
Mr Tyers was travelling to the Chinese port city Ningbo for academic research in May.
And the climate-conscious scientist told CNN that he felt compelled to stop flying when UN climate experts warned last year the world had less than 11 years to avoid catastrophic levels of global warming.
Tyers says his train journey to China produced almost 90% less emissions than a return flight.
"It's hard to understand how polluting air travel is and the amount of energy and kerosene it takes to put people in the air and get them across the planet," he said.
Thousands of people worldwide have publicly pledged to stop flying, including teenage activist Greta Thunberg, who has inspired youth climate protests around the world.
Activist Maja Rosen launched the "Flight Free" campaign in Sweden in 2018 with the aim of encouraging 100,000 people not to fly for one year
Although only around 14,000 people signed the online "#flightfree2019" pledge, Rosen told CNN that the campaign had made more people aware of the urgency of the climate crisis and motivated them to travel by train more often.
The campaign sparked a wave of social media posts showing people traveling by train, accompanied by the hashtags #flygskam and #tågskryt, which mean "flight shame" and "train brag" in Swedish.
Ms Rosen told CNN: "One of the problems is that people feel there's no point in what you do as an individual.
"The campaign is about making people aware that if we do this together, we can actually make a huge difference.
"A passenger's footprint from an individual flight depends on a number of factors, including how far they fly and how full the plane is, but also on what class they travel in: First class passengers are given more space than economy passengers, meaning they're responsible for a bigger proportion of the plane's emissions.
"Emissions from train travel also depend on many factors, including how the train is powered. An electric train powered by clean energy will have much lower emissions than a diesel-powered train, for example."
Greta Thunberg was today named one of this year's ten people who "mattered in science" by prestigious journal Nature.
The 16 year-old-climate change activist is hailed alongside a neurologist who brought pigs' brains back to life and a palaeontologist who shook up humanity's family tree.
The world famous British magazine, which celebrated its 150th anniversary this year, says the Swedish youngster "channelled her generation's rage".