"We young people don't have the vote, but school is obligatory," Greta explains when The Local visits the site of the protest on its fifth day. "So this a way to get our voices heard."
The flyers she has with her for passersby to read use even stronger wording: "We kids often don't do what you tell us to do. We do as you do. And since you grown-ups don't give a shit about my future, I won't either." She is refusing to attend school – something which is obligatory in Sweden up until the age of 16 – until after the September 9th vote, in an attempt to raise awareness of climate policy.
Greta said she learned about the effects of climate change mostly at home, and began to get engaged in environmental issues from the age of 11 or 12.
"The more you read, the more concerned you get," she says. "It's obviously worrying, but I think that instead of worrying about something that can happen, you should try to change it as long as it's possible to make a change."
"I have gone to climate demonstrations and things like that before, but this is the first time I've organized something myself," the 15-year-old adds.
A passerby stops to congratulate Greta and give a gift of chocolate. Photo: Catherine Edwards/The Local
The strike has been taking place every schoolday since term began, roughly between the hours of 8.30 and 3.30pm. This means missing three weeks of school in total, so is Greta worried about missing out on the start of the year? "A little bit, but I have my books with me," she explains, adding that she is making sure to keep up with what her classmates are working on.
As for how her parents (her mother Malena Ernman is a well-known opera star and climate activist) feel about her missing school to protest, Greta tells The Local: "Of course they think I should go to school, but they understand why I'm doing this; as fellow humans they think it's good, but as parents they think it's bad."
And so far her protest has gained far more attention than she expected. "I thought I would be sitting here by myself," she admits.
That's far from the case: around ten people had joined the strike when The Local visited on Friday morning; by the end of the previous day, the number was 35.
A group of parents and their children who joined the protest. Photo: Catherine Edwards/The Local
"There's another student here today, there have been a lot of parents who have brought their small children with them. My teacher was here yesterday, and today there are other teachers here," says Greta.
Several politicians have come to speak to Greta, including Minister for Social Affairs Annika Strandhäll, Left Party chairperson Jonas Sjöstedt, and several members of parliament from both sides of the political aisle.
She has also been joined by Fatemeh Khavari, who has been acting as a spokesperson for the young Afghans protesting against Sweden's deportation policy. Greta's protest has been covered widely by Swedish newspapers and TV, with one columnist calling the 15-year-old "Sweden's own Malala", referring to the Pakistani activist for female education Malala Yousafzai.
The choice of location means that dozens of professionals and tourists alike pass by the group all the time, many stopping to read the photos, some wanting to shake Greta's hand and congratulate her effort. One man brings chocolate bars with him as a gift.
"It's a good response, some people go past and give us a thumbs up, some come and take a flyer, some come and sit with us. It's mostly very positive," says Greta.
Perhaps that's no surprise, since an extreme heatwave and widespread wildfires this summer have pushed climate issues up the agenda for many voters. Some surveys show that climate policy is now the second most important issue for voters ahead of the September 9th election, with only immigration considered more pressing.
Greta hopes her protest will help ensure the question stays at the top of the agenda, and says politicians could show they take it seriously "by talking about it, by prioritizing the climate, by treating it as the crisis it is".
