In August 2018, 15-year-old Greta Thunberg sat in front of the Swedish parliament building to protest for greater action on the climate crisis. She wanted the government to pledge to reduce carbon emissions.


A month later, on the day before the Swedish general election, Greta announced that she would continue to strike every Friday until the country’s policy changed. Her slogan was FridaysForFuture, which went on to represent the global school’s strike for climate.

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Now, a year later, students and adults around the world have joined strikes for FridaysForFuture, as well as the UK-based organisation Extinction Rebellion. XR, as they’re widely known, began around the same time as Greta’s first strikes, and are a group of nonviolent protesters who want to communicate, and stop, the threat of mass extinction by climate change.

XR’s first act of civil disobedience was in October 2018, when a crowd of 1,500 gathered in Parliament Square. In the following weeks, they blocked bridges and glued themselves to the gates of Buckingham Palace. Through the disruption, they wanted to bring attention to the climate emergency.

In the 12 months since that first protest, the movement has grown to see 150,000 people on the XR mailing list. There are 156 different countries with at least one XR rebel, with groups in Australia, the USA and Ghana, to name just a few.

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Roger Hallam, one of the XR founders, claims to have been inspired by the 2011 book Why Civil Resistance Works. The book’s co-authors, Erica Chenoweth and Maria J. Stephan, collected and analysed data on over 300 violent and nonviolent major political campaigns in the last decade.

They found that nonviolent campaigns had been twice as effective as the violent campaigns: they succeeded about 53 per cent of time compared to 25 per cent for an armed resistance. This success of civil resistance is the backbone of the XR movement – any action attributed to the organisation must be nonviolent, and being arrested is not a requirement of getting involved.

Stephan is now a director of the Program on Nonviolent Action at the US Institute of Peace. She notes that a campaign cannot just be a one-off protest, it has to be a sustained sequence of actions – not just protests – to have any chance at success.

“Some of the most powerful tactics in nonviolent resistance can be refusing to buy products or ‘stay at homes’ – non-cooperation with the status quo,” says Stephan. “We don’t claim that nonviolent resistance always works,” she stresses. But both in terms of immediate and longer-term impacts, nonviolent resistance seemed to produce more positive and beneficial results.

A democracy initiated by a nonviolent movement was less likely to fall back into civil war, for example. In the 2011 Arab Spring, several countries had anti-government protests. Nonviolent street demonstrations in one of these countries, Tunisia, led to the overthrowing of the president and eventually democratisation of the country.

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Stephan’s co-author Erica Chenoweth took their research further and found that no regime or incumbent leader had remained in power when at least 3.5 per cent of the population had participated in active protest. That’s not to say success is guaranteed when a movement attracts 3.5 per cent of a population. “Of course, it’s sustained participation over time, keeping people actively involved, that’s needed,” explains Stephan.

So how does a campaign attract people and then keep them engaged?

Psychologist David Halpern, director of government partner The Behavioural Insights Team, likens the dissemination of an idea to the adoption of an innovation, or piece of new technology.

The same way mobile phones have spread from an elite few to become a part of everyone’s daily lives, the uptake of an idea within society follows a set pattern. The pattern was suggested by Everett M. Rogers in his book Diffusion of Innovations.

First, there are innovators, the ones who champion something from day one. These then influence ‘early adopters’, people who are “considered by many to be ‘the individual to check with’ before adopting a new idea,” writes Rogers. These in turn influence the majority, then finally, the ‘laggards’ – “those who tend to be suspicious of innovations and of change agents.”

Greta Thunberg is an example of an innovator, says Halpern. “She personifies a lot of this. She’s persistent and authentic. One of the things that undermines a message is if you yourself are not consistent. Then people will just view you as hypocritical. She embodies it.”

Key to the adoption of an idea is the ability to recruit past the innovators and early adopters. “The protests that grow to scale are able to recruit people. And if you get that wrong, you won’t get your early majority assembled,” says Halpern.

In the climate movement, it’s the younger generation who are the early adopters. “Teenagers are almost wired to be contrary, to be a bit rebellious,” notes Halpern. “They are able to recruit and persuade the more reluctant older folks.”

Elements of a protest can dissuade people on the fence from joining a movement, though. “We’re built to absorb information which supports our prior beliefs,” explains Halpern.

This means that if you were sceptical about climate change and were then met with angry protestors blocking your route to work, you’ll ‘asymmetrically absorb’ this information and it’ll give you an excuse not to adopt.

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But not everyone has to be completely on board for a movement to work. The early adopters just need to influence the majority enough.

“[The majority] might not be thinking ‘I’m prepared to go to extraordinary lengths to change my lifestyle’ but they create a critical mass such that you get adoption of electric vehicles, smart meters, etc,” says Halpern.

With the number of people joining both XR and FridaysForFuture growing, what can we expect to see next?

In Stephan and Chenoweth’s research for Why Civil Resistance Works, they found that the average time for a nonviolent campaign to achieve its goals was three years.

“Three years was for maximalist campaigns with major political goals, which is not to say the climate movement will take any shorter or longer, but there are different variables and different mechanisms of change,” explains Stephan.

“It’s hard to put a timeline on it. But scientists demonstrate that time is running out [for climate action].”

Stephan and Chenoweth found that the average duration for violent campaigns was three times that of nonviolent. “Oftentimes people will say ‘nonviolence isn’t working, we need to take up arms to win more quickly!’ but there’s not a lot of evidence that that is the case.”

Stephan says she has friends and colleagues who are involved with the protests and will probably show up herself for some of the Washington, D.C. portion of the strikes.

“Certainly, the youth face [of the movement] is really powerful,” she says. “It’s gotten lots of new and different people involved and actively engaged in what is probably the most pressing issue certainly of my generation.”

  • This article was first published on 27 September 2019
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Amy ArthurEditorial Assistant, BBC Science Focus

Amy is the Editorial Assistant at BBC Science Focus. Her BA degree specialised in science publishing and she has been working as a journalist since graduating in 2018. In 2020, Amy was named Editorial Assistant of the Year by the British Society of Magazine Editors. She looks after all things books, culture and media. Her interests range from natural history and wildlife, to women in STEM and accessibility tech.