‘As more join, it gets less risky’: how Greta Thunberg’s lone strike turned into a movement

https://www.theguardian.com/environment/2025/sep/04/greta-thunberg-school-strike-movement

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In an extract from his new book, Tim Lenton explains how Fridays for Future challenged climate inaction to reach a positive tipping point

In August 2018, Greta Thunberg was sitting alone on the ground outside the Swedish parliament with a placard reading “Skolstrejk för klimatet” (School strike for climate) and a bunch of pamphlets under a stone.

An older woman stood over her and asked: “Why are you on strike? You have to go to school.” Greta retorted: “Why would I need an education if there is no future?”

“If you get an education, you can affect the future,” replied the woman. “That’s what you’re supposed to do, you children and young people. For us old people it’s too late.”

“It’s not too late,” said Greta. After a few more exchanges the woman walked away, looking dismayed.

A younger woman stopped: “Hi. May I sit with you?”

“Yeah,” said Greta.

“I just wanted to say that what you are doing is so cool,” said the woman. “Do many people stop?”

“So far today it’s been three,” replied Greta. They sat together. Then a young man, with his bike helmet still on, stopped and asked: “How long have you been sitting here?”

Soon others too began to stop, read the pamphlet, and join in. All this is captured in the opening sequence of Nathan Grossman’s documentary I Am Greta. Within seven months a million people had joined the Fridays for Future school strike movement.

The dynamics that start a social movement such as Fridays for Future are quite general. In a famous Ted talk, Derek Sivers narrates a video that starts with a lone, topless man dancing wildly on a grassy slope at what looks like a festival. A bunch of other people are sat on the grass nearby, no doubt thinking: “Who is that crazy guy?”

But then something happens: another man gets up and starts to join in the dance, imitating the moves. The first man immediately greets him as an equal, taking his hands, and they start dancing together.

Now it is about them, not just him. As Sivers beautifully puts it, “that first follower is what transforms a lone nut into a leader”. The first follower shows everyone else how to join in. He immediately starts calling and gesticulating to his friends to come over. A second follower joins the dance, emulating the first follower, with wild exuberance. Three is a crowd and they start to draw attention. Two more people join in, and straight after that, three more. Then it snowballs.

As Sivers puts it: “This is the tipping point. Now we’ve got a movement.” As more people join in, it gets less risky for the next person to join, because they won’t stand out or be ridiculed. Pretty soon the dynamics flip – even those who were reluctant to get up feel compelled to join in the dance, because they want to be part of the in-crowd and the new status quo.

This is how a social movement can reach a tipping point: both Greta and the lone dancer successfully challenged social norms – of going to school rather than protesting, and of not making a spectacle of yourself in public. In Greta’s case she was trying to change another set of norms – of inaction on climate change. There is a social barrier to instigating change. It takes a particular kind of loner courage to be the first dancer that starts to move against the tide. That action must be public, and breaking established norms may be challenged, ridiculed, or simply ignored. In Greta’s case, she was vilified in parts of the media. But by setting a precedent, the first dancer invites others to join them and challenge the status quo.

The first follower closes a reinforcing feedback loop and makes it easier for the next person to also break from norms and join in. Each subsequent person joining the movement makes it easier for the next person to join, and so on, creating an amplifying effect. If that amplification is strong enough, it can reach a tipping point. At a critical mass, the social incentives reverse, and change becomes self-propelling.

At the start of a social movement those choosing to join in change their actions but not their views. They already agree with the values being expressed by those in the movement – they like dancing or they are convinced that climate change is an existential threat that politicians must take more seriously. It is just that beforehand they weren’t brave enough to break from the status quo until they saw others join in.

At some point, however, a movement can start to tip the views of people previously indifferent or even opposed to the position taken by the movement. Abolishing the slave trade, votes for women, equal marriage and legalising abortion in Ireland are all examples of what beforehand seemed impossible and afterwards seemed inevitable.

Later, we hear the self-congratulatory remarks from those we know once flatly opposed it: “Of course, I have always believed in the movement.” This is very human. We do not like to stand out from the crowd and when it changes, we change.

And such change can go as deep as rewiring our worldview and beliefs. This is good news, because to avoid climate tipping points we need to transform the social world, and for some of us that will involve changing how we see the world.

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Greta clearly had an epiphany, a shift in worldview, as she read more and more about climate change. As she put it: “One thing that I found very scary is tipping points, that once we reach tipping points, then there’s no going back. Then we start a chain reaction beyond our control.”

Her response was “instead of worrying about how [the] future might turn out, you should try to change it while you still can”. Greta managed to trigger her own chain reaction by striking from school. With her first followers she triggered a social tipping point of escalating climate protest. But Greta and the many millions that have joined her are fighting for a much bigger tipping point.

Greta’s aim was to trigger decisive political action to tackle climate change. If we look at what that change entails, it is profound as well as diverse. Ultimately it involves tipping societies from an unsustainable state to a sustainable one. Central to this is tipping an economy powered largely by fossil fuels into one that has been decarbonised. To achieve this overall tipping point will require a myriad of more specific tipping points. It demands a tipping point in social norms. For some there will be shifts in worldview. There need to be tipping points in the diffusion of technology. Tipping points in governance would help.

For now, let’s crudely sketch the big picture. We can represent the situation as a current unsustainable, fossil-fuelled state of societies – the status quo – and an alternative sustainable state, with a barrier between them. That barrier exists for a multitude of reasons. We are to varying degrees locked in to existing systems, including existing habits, technologies, infrastructures and ways of thinking.

While most of us just go along with the status quo and some like Greta actively oppose it, others are actively maintaining it. They tend to be those who benefit most from things staying as they are, and those who feel most threatened by change. These incumbents participate in feedback loops that maintain the status quo.

For example, the fossil fuel industry buried its own studies of climate change and instead spread doubt about the science. It also actively lobbies governments for support. Governments provide subsidies and tax credits for fossil fuel extraction and use. Banks fund extractive industries. The fossil fuel industry in turn pays banks back with share dividends, and governments back with (mostly) content voters. All this helps keep the incumbent state stable.

To get out of the incumbent, unsustainable state we need a fundamentally social tipping point, because it is people and their actions that either maintain the status quo or oppose it.

For those who decide the existing system must change, there are complementary ways of trying to achieve that. We can work to weaken the damping feedback loops that maintain the status quo. Or we can work to strengthen the reinforcing feedback loops that can amplify change.

Social movements, like the suffragettes or the climate protesters, are a particularly important way of tipping change. Many, if not all, of the great social changes in the past had social movements behind them. To achieve their political goals, social movements leverage the reinforcing feedback of escalating protest to increase political pressure on incumbents. By targeting and publicly opposing the incumbents, they tend to focus on weakening the damping feedback loops that maintain the status quo. For example, campaigning for divestment from fossil fuels.

But we can also all be part of strengthening reinforcing feedback loops that amplify positive change. Just by adopting a lower-emission technology or behaviour (like eating less meat) we encourage others to join us. This is because of social contagion – the more people who adopt something, the more others they can influence to adopt it.

With technologies there are extra amplifiers of increasing returns: the more of us who adopt a new technology, the better it will get (through learning-by-doing), the cheaper it will get (due to economies of scale), and the more other technologies will emerge that make it more useful. This is what is making solar PV panels, wind turbines, and electric vehicles ever cheaper, better, and more accessible.

Positive Tipping Points: How to Fix the Climate Crisis is published by Oxford University Press