It's a hot, sunny day in a park in the western Swedish city of Gothenburg and people sit in small groups dotted along the green grass. Standing on a nearby path, a woman with long, strawberry blonde hair approaches people walking past.

"Would you be willing to give up flying for a year?" she asks one man.

"No, but I fly for work," he replies.

She asks: "And there's no way to avoid it?"

"No, I think driving to Taiwan would be a bit difficult," he says.

After another couple of minutes of talking the man walks off. Despite the rebuff, Maja Rosén smiles. She's spoken to a number of people today and most, she says, have had a different reaction.

"Out of all those people I've spoken to so far, more people are actually willing to do this than to say they don't. That's a big change to last year," she said.

Last year, Rosén and her neighbor Lotta Hammar started a campaign to try to convince people in Sweden to give up flying for one year if 100,000 others also pledged to ditch flights. 

They were only able to gather around 14,500 signatures, so they're trying again this year. So far, they have almost 5,000 pledges. Still some way off, but Rosén isn't concerned.

Read more: How to get from Europe to Australia without flying

Swedes spreading 'flygskam' or 'flight shame'

Flight-free 2020 is part of a larger movement gaining ground in Sweden and spurred on by environmental activists like Greta Thunberg and Olympic athlete Björn Ferry who've been in the headlines for, among other things, their decisions to forego flying.

There's even a new word that has even been coined to describe the feeling now being felt by some who fly: flygskam or "flight shame."

Rosén said wider knowledge about the movement has made the campaign easier.

"I think that really shows how much we are affected by each other, because now everyone has heard about the flying debate and they are rethinking their flying," she said.

The link between flying and CO2

Flying contributes more than 2% of global carbon emissions and is set to rise. Global passenger numbers almost doubled from 2008 to an estimated 4.37 billion in 2018. And the International Air Transport Association estimates that it could almost double again to 8.2 billion passengers by 2037.

Swedes are among the most prolific travelers in Europe. A population of just under 10 million people, they made more than 59 million trips in 2017 —  or roughly six trips per person, according to Eurostat.

Yet, the number of Swedes taking domestic flights  is falling. Domestic passenger numbers fell by 3.6% in 2018, according to Sweden's Transport Analysis, the government agency charged with providing transport statistics.

And while the number of people flying through Sweden's airports grew overall by 1.1%, it was the lowest annual growth recorded since the economic downturn in 2009, the agency reported.

The Swedish agency cited the "current climate debate" as part of the reason for the fall in growth.

Meanwhile, there's been an uptick in train travel.

1.5 million more train travelers in 2018

A journey that would take just over an hour flying takes five by train. But that's not stopping many of the passengers traveling from Malmö in southern Sweden to the capital Stockholm.

A young man with floppy, blonde hair said he's given up flying. "It doesn't work. You can't do it anymore."

In 2018, Swedish state rail operator SJ saw a record of almost 32 million journeys — an increase of 1.5 million from the year before and up almost 4 million from 2016.

But it's not all people who are definitive about staying grounded. A couple of carriages down, a young woman in a baseball cap said she knows about the anti-flying movement in Sweden, but is not sure about giving up planes altogether.

"Sometimes, I fly. It depends on the cost because it's crazy but sometimes it's much cheaper to fly between Malmo and Stockholm. I don't want to, but I do it anyway, sometimes."

An older Swedish couple, however, have not heard of the no-fly movement and they don't think people need to stop flying. "What we do here, it doesn't matter," said the man. "We are 0.01 % of the whole world."

Business foot forward

Still, whether or not the no-fly movement has spread, it is providing lift off for some businesses. "Tagsemester" — meaning "train vacation" — was founded as a Facebook page providing tips for train travelers.

At the beginning of 2018, it had 4,000 members. Just over a year later, there are almost 100,000 and a new business, launched by Susanna Elfors and Andreas Sidkvist. The firm offers group train tours, markets Interrail cards and organizes conferences for train enthusiasts.

"The cool thing now is that we're in the middle of this shift, where people go from having been flying and that's the normal thing, to feeling ashamed about flying and to start thinking about other ways to travel," said Sidkvist. "Train travel has been like a hope for many to still be able to travel but in a more climate-friendly way."

Making train travel more competitive remains a challenge. Airlines have benefitted from a lack of tax on jet fuel and limited taxing of flight tickets over the past years. As a result, it's often cheaper than traveling by train and can take a fraction of the time.

Environmental psychologist Kali Andersson believes that although the no-fly campaign has the potential to make real change in the long run, it will need help in the form of governmental regulation.

"The best way to change people's mindsets and norms, which is the case here, is actually by binding politics. So we need laws to regulate it," she said. "But politicians will not make this decision if they think that the whole people will become very upset with them or they would lose the next election. So we still need support from the people."

Coming down to earth

Maja Rosén first gave up flying because of her concerns about the climate. She's also a vegan and tries to keep her carbon footprint to a minimum. At first she didn't talk much about it for fear of alienating her friends. Having her second child and feeling concerned about the world she would be leaving her children prompted her to speak out.

Her neighbor was among the first she talked to. A frequent flyer, he took the drastic step of giving up air travel completely.

"I think it's not about that people don't want to make sacrifices, because in other situations we're willing to do so much," said Maja. "I think that's the problem, that most people — politicians and researchers — they don't really talk about climate change in a way that makes people understand that it's here and now, that we just have to do this."

Although, Flight-Free 2020 has garnered less than a tenth of its intended signatures, the Swedish movement has crossed borders with other activists trying to convince 100,000 people in Germany and the UK not to fly.

Whether Rosén reaches her target or not, she's happy to know the message is spreading. 

"The people who sign up have to feel engaged in this and try to also convince people around them," she said.

"I think that will be easier the closer we come to New Year's Eve because right now 2020 feels a bit distant to many people."