One of New Zealand's best-known scientists has vowed to be "kinder to our climate" by swapping planes for trains this year.
University of Auckland physicist and science commentator Professor Shaun Hendy wants to set an example to others with his one-man campaign, dubbed #nofly2018.
Already, that's meant travelling to Wellington by train - and heading back to Auckland by overnight bus.
Hendy was inspired by a talk by Professor Quentin Atkinson, a fellow Auckland University researcher and an expert in how cultures change and evolve, who explained why we believe things even when there is no evidence, or the evidence is against us.
"He made the point we often put faith in people who make sacrifices that demonstrate the strength of their conviction," said Hendy, who directs the university-based centre of research excellence, Te Punaha Matatini.
"People who walk the talk can be more convincing than those who just talk."
That got him thinking about scientists and climate change.
"We tell people the world is warming as we continue to emit carbon dioxide, yet the typical scientist has a much bigger carbon footprint than the average person, because of the travel we do."
"Traveling to Antarctica for field work or presenting your work at a conference in Hawaii is one of the perks of the job."
Because of this, there was a growing movement in science to reduce the amount of traveling scientists do.
Global air travel accounts for 2.5 per cent of the world's greenhouse gas emissions - roughly the same contribution as Germany - and mobility accounts for a large proportion of science's carbon footprint.
Recent research has found that climate researchers with low carbon footprints were viewed as more credible than those whose personal energy use was high - something that led many to question climate campaigner Al Gore's own carbon footprint.
Some figures in science, like the Jet Propulsion Laboratory's Peter Kalmus, had now stopped flying altogether.
"I thought I would try something less drastic - not flying for a year - hoping that it might be something that other scientists would try."
For Hendy, who works closely with the Government on a range of projects, and who found himself flying to Wellington at least once a month last year, his self-imposed air-ban wouldn't be easy.
But he had some ways to work around it.
"This year I'll take the train or bus down and stay for longer - replacing a couple of dozen flights with a few train trips and a lot of video-conferencing," he said.
"I think it is doable if I plan well, but it will mean missing some events and spending more time away from home."
Hendy has also been working for nearly 10 years with scientists at the University of Sydney on how to use nanotechnology to produce clean water.
While they meet regularly via video conference, the collaboration typically involves at least one or two face-to-face sessions a year.
"This year we may find it more difficult to crack some of the challenges we are still work."
His first big overland trip, fittingly, was to last week's Pacific Climate Change Conference in Wellington, and proved the first time in 30 years that he'd taken a train through the North Island.
"It was a beautiful journey, and I was able to work most of the way on my laptop.
"But I was surprised to find it only goes three times a week, which meant I had to go down on a Saturday for a Monday meeting.
"It also means I will have to go back by bus, which won't be as easy to work on."
Hendy said Atkinson was joining his effort, and others colleagues had also shown some interest in doing the same.
"The climate is changing, not in a good way - it's bad, and it will be much, much worse unless we get our act together."
"I hope people see what we are doing and get the message that scientists are worried about the climate."
"I also want to show that it's possible to make changes in the way we live and work to be kinder on our climate.
"It's actually up to those of us who, like scientists, live relatively privileged lives to make these changes first.
"We have the biggest impact and are best equipped to make the changes."