On 20 August 2018 a lone Swedish teenager started her school strike for climate outside the Swedish Parliament. Roughly six weeks later, the Intergovernmental Panel on Climate Change (IPCC) published its Special Report on Global Warming of 1.5 °C. And at Halloween, roughly 1500 people assembled in London’s Parliament Square for the very first Extinction Rebellion (XR) demonstration.

All three of these events made atmospheric chemist Scott Archer-Nicholls of the University of Cambridge, UK, question his assumptions about the future. “The rate these movements [the school climate strikes and XR] grew took me by surprise, I did not think I would see their like until it was too late,” he told Physics World.

When Archer-Nicholls read the IPCC 1.5 °C report, it became clear to him that he “did not want to live in a 2° C warmer world, and it would be a betrayal of both my future and present generations of children to stand idly by and let that happen”. Although the report contains little new science – it’s an overview and synthesis of already published findings — Archer-Nicholls believes it marks a step change in communication by the IPCC, laying out “the stark outcomes of our choices in a much more direct way to previous reports”. As he read the differences between a 1.5° and 2° C warmer world, one fact really affected Archer-Nicholls: that 70-90% of coral reefs would be wiped out at 1.5 °C, while more than 99% would be wiped out at 2 °C of warming. “Aside from the devastating impact this would have on the fishing industry and the many people who depend on fish to get enough protein, it is simply a tragedy that keeping the warming to a limit considered ‘safe’ in climate negotiations would completely wipe out the most diverse ecosystems in the world’s oceans,” he says. “And we would do so knowingly, with the technological capability to prevent it.”

The IPCC report also makes clear, according to Archer-Nicholls, that to have a good chance of staying below 2 °C of warming, let alone 1.5 °C, requires a massive level of emission reductions “especially if you think it is prudent to not rely on future mass deployment of unproven technologies to remove carbon dioxide from the atmosphere”. Our current efforts will likely see temperatures rise to more than 3 °C by the end of the century, “a level of warming scientists agree would be devastating”. Last year, global carbon dioxide emissions increased by 2.7%, the fastest rise for some time.

Many climate scientists I have spoken with over almost a decade are deeply pessimistic about seriously addressing emissions, but publicly make positive noises

Kevin Anderson

As well as this IPCC report, the school climate strikes and XR, the rise in extreme weather events around the world also made an impression on Archer-Nicholls. These have, he says, been coming much faster than expected even a few years ago and it has become undeniable to attribute them to climate change. “It was the last two summers where I felt in my gut that it was too hot for the UK,” he adds. “These really put me on edge and made me not know but directly feel that climate change is here already.” To date the planet has only warmed around 1 °C. “If that alone could make me feel so psychologically out of place in my own country I did not want to experience anything more, yet I know that more is coming.”

Like a true scientist, over Easter 2019, Archer-Nicholls set out to make some observations — of Extinction Rebellion’s April protests in London. He describes the experience as enlightening. “I found the mix of people there to be much broader than I was expecting, many not typical activists,” he says. “People seemed genuinely worried about climate change and were involved for good moral reasons. I was impressed with the organisation of the movement, the commitment to nonviolence and an excellent relationship with the police, all of which meant the protests had a remarkable amount of public support given the disruption.”

But there’s a but. Archer-Nicholls also found “a distinct lack of other scientists involved, a generally quite low level of understanding of climate science and the politics around it, and the proliferation of a lot of alarmist misinformation, signs of which I had seen before [when] reading news reports of XR, which had partly put me off getting involved sooner”. That said, Archer-Nicholls also saw that this movement “was going to keep growing whether scientists were involved in it or not”, and that it had done more to shift the debate on climate change in two weeks than he’d seen from any of the official discussions on climate change in the 10 years he’d spent as a researcher.

Human vs scientist?

From these observations, Archer-Nicholls drew some conclusions. More on that later. Not every climate scientist sees taking a view on what society should do as part of their professional remit; a factor that’s perhaps responsible for the lack of scientists involved in XR that Archer-Nicholls observed. Although scientists have a human face too.

“In our professional roles as scientists we should not at all be advocates for change,” Ken Caldeira of the Carnegie Institution for Science, US, told Physics World. “I am an academic research scientist and my role is to generate useful information, and not to opine about what should or should not be done.” In his role as a human being, however, Caldeira is sympathetic to the broad goals of Extinction Rebellion. “It is both laudable and inspiring when people put what they see as the well-being of the planet ahead of short-term personal self-interest,” he says. “In our roles as humans on this planet, we [scientists] have the same responsibilities as everybody else. When you see the possibility of your society going down a better path, it seems that there is a civic responsibility to argue that society consider going down that path.”

Simon Lewis, a global change researcher at University College London and the University of Leeds, UK, also has thoughts on this scientist/human duality. “In my view it is fine for scientists to advocate for change, but they must take care,” he says. “Scientists must do their best to be as scrupulously honest in analysing the data and reporting it as is humanly possible. But that should not be traded-off against expressing political opinions in a separate arena. Being clear when you are speaking as a scientist and separating when you are speaking as a citizen, or on behalf of a group can help.”

Terry Rankin, an XR local organizer from Orlando, US, whose interests include philosophy of science, believes that value-free science “leav[es] scientists on the horns of a dilemma – be a scientist or be fully human, but not both”. Rankin has seen scientists in XR say that as advocates of change, they must act only as persons, not as scientists. “Science, in other words, has no voice in ethical conviction or in moral action, and conversely, ethics and morality have no place in science,” he says. Rankin sees the truth as the opposite. “The strongest evidence supporting ethical principles and consequential moral values and actions is the scientific evidence.”

Kevin Anderson, a professor of energy and climate change at the University of Manchester, UK, feels that climate change is an issue on which scientists cannot be politically neutral. “For many years I have been deafened by the silent roar of academics unprepared to speak out, and consequently, through their silence, [they] vociferously support the status quo; that is a deeply political position,” he says. “Others have been more actively co-opted by the established system, believing that we need to keep our advice in line with current economic thinking, or we will be ignored.” And then there are those who see climate change as a deeply political issue and openly engage with it through a political as well as technical/scientific lens, according to the researcher.

I have always found the huge gulf between what scientists say is needed to mitigate climate change and what politicians are prepared to do about it so obviously mismatched it would make me feel sick

Scott Archer-Nicholls

Anderson reckons the academic community has broadly abdicated its responsibility to speak truth to power, choosing instead to care about political and economic sensibilities and fine tune its assumptions to ensure its conclusions on mitigation fit within the existing economic paradigm. “Privately, many climate scientists I have spoken with over almost a decade are deeply pessimistic about seriously addressing emissions, but publicly make positive noises,” he says. “The Integrated Assessment Models repeatedly mask the scale of the mitigation challenge, and ignore the clear equity language and steer in the Paris Agreement.”

Archer-Nicholls too has views on the mismatch between science and politics. “I have always found the huge gulf between what scientists say is needed to mitigate climate change and what politicians are prepared to do about it so obviously mismatched it would make me feel sick,” he says. “Yet there seemed to be a strange double-think going on in most of the profession to not openly acknowledge it and praise any attempt to address climate change, no matter how insufficient. In that light, I found the candid approach of XR and the school strikes to call out this hypocrisy and not accept anything short of what scientists say is needed quite cathartic.”

Lorraine Whitmarsh, an environmental psychologist at Cardiff University and director of the UK Centre for Climate Change & Social Transformations (CAST) agrees that neutrality is tricky. “I don’t think planetary and human health are things which one can be neutral about – they are surely unambiguously good!” she says. “So while as climate scientists, we may need to stop short of advocating specific policy solutions to climate change – which is something that society, via elected politicians and deliberative democracy, should ultimately decide on – we can shape that debate through research showing the impacts of different options, e.g. if we adopt low-carbon diets, we reduce climate change risks and improve health.” According to Whitmarsh, while some argue that scientists should remain “neutral” to retain their credibility, evidence from Attari and colleagues in the US shows that climate scientists are less credible if they have high-carbon lifestyles. Whitmarsh believes that if scientists personally demonstrate those behavioural changes required to mitigate and adapt to climate change, this not only improves their scientific credibility but also helps demonstrate what is possible. And that changes social norms and attitudes. As, indeed, may the XR protests, as we’ll hear from several researchers later.

Conservation scientists Charlie Gardner of the University of Kent, UK, and Claire Wordley of the University of Cambridge, UK, seem to take it one step further. They believe researchers “must act on our own warnings to humanity”, as they wrote in a paper in September 2019 that calls for scientists to join civil disobedience movements to fight the unprecedented crises in climate and ecosystems.

Acting for good?

As we’ve seen, there’s a range of views on the intersection between scientists’ roles as professionals and as citizens. Each much choose their own path. Lewis moved to action on the XR front ahead of Archer-Nicholls (and ahead of Gardner and Wordley’s call to join the fight). Back in December 2018, this UCL professor signed a letter of support for XR to UK newspaper The Guardian, alongside 99 other academics from a range of fields, authors, politicians and campaigners. “Scientists often bemoan that their interests are not reflected in parliaments, but if we want more scientists to engage in the policy work then we will need to be more welcoming of scientists expressing political views,” he says. Lewis has attended XR protests and blockades as well as a neighbourhood families meeting near his home. “I believe that a lot of important social change comes from grassroots movements of people working together, from the decolonisation movements in the last century, to the women’s rights campaigners, to anti-racist struggles,” he adds. “Tackling the escalating environmental crisis will require similarly escalating and enduring grassroots action.”

Science, in other words, has no voice in ethical conviction or in moral action, and conversely, ethics and morality have no place in science

Terry Rankin

Four months after Lewis signed the letter, Archer-Nicholls’ observations at the April XR protests led him to a firm conclusion. He should act. He believes that the core premise of XR and similar movements is correct. “We have delayed for too long without sufficiently tackling the causes of climate change, which means urgent action is now needed; governments and media have not been honest enough to the general public about the risks; and if we don’t address the issues soon the climate and ecological crises have the potential to become existential threats, justifying the use of nonviolent direct action to effect change, and meaning failure to address it in time is an ethical failure on future generations,” he says. “The inaccuracies, exaggerations and misinterpretations of the science are largely details against this broader backdrop of a legitimate call for action. However, I think they can do real damage by undermining the credibility of the movement, putting off important actors from being involved and basically contradicting the first demand – ‘tell the truth’.”

Extinction too far?

Other scientists have expressed reservations about XR’s understanding or use of the science too. “Some of the science claims made by Extinction Rebellion activists go a bit over the top,” says Caldeira. “Even the name — while many species are threatened with extinction, climate change does not threaten human extinction. This raises the question of the extent to which people are motivated by accurate facts and how much they are motivated by extreme, and very likely false, claims. I would not like to see us motivating people to do the right thing by making them believe something that is false.”

Whitmarsh thinks some of XR’s views seem unrealistic. “In particular, they appear to call for net zero [carbon emissions] much earlier than most scientists say is possible (or necessary),” she says. That said, the researcher does support many of the aims of Extinction Rebellion, including the need for urgent action on climate change and the importance of citizen involvement in decision-making. Archer-Nicholls is also not convinced that net zero is possible by 2025. “Having said that, I do think it plays an important role in shifting the debate toward considering emission cuts that might be enough,” he says. “As a proposal I think it less ridiculous than countervailing arguments from climate deniers that we don’t need to have any policies to mitigate emissions, views which until recently have had an unreasonable level of coverage in the media and undue influence on global politics, particularly in countries such as the US, Brazil and Australia. At this point in time the risks of not addressing climate change fast enough are both more dangerous and more likely than the risks of overcommitting.”

Archer-Nicholls also has concerns about the “12 years to save the climate” message and “emergency” language echoed by both XR activists and school strikers. “One of my main worries with this messaging is that it can give people the false impression that if we fail to address it soon there will be a cliff-edge disaster, and that these views might fuel anxiety and depression or lead to rash decision making” he says. “I find this really concerning, the world is not going to suddenly end in 2030 if we don’t reduce carbon dioxide emissions, and the global heating that does happen over that time-frame is largely insensitive to whether or not we reduce emissions in that period.” The next 5-10 years, he believes, are critical if we are to prevent the worst impacts of climate change, but so are the 10 years after that. “We won’t know [until] several decades after that whether we have done enough to actually prevent disaster,” he explains. “This lag between action and outcome is a key reason why it is such a difficult problem to deal with politically, especially in democracies with 4-5 year election cycles.”

Anderson, on the other hand, sees XR and other campaigning organizations as being more in tune with the science. “Very sadly, I think XR and indeed much of the language forthcoming from the Youth Climate Strikes, is more in line with the science and commitments enshrined in the Paris Agreement than the public statements made by many climate academics, ‘experts’ etc.,” he says. “XR and the Youth Strikes are helping academics, particularly earlier career colleagues, find the courage to speak out publicly the views they hold privately.” [CLARIFICATION 23 September: Archer-Nicholls also feels that the messaging of the school strikes and XR, if anything, conveys the urgency of the situation better than official reports or experts. His comments regarded some of the specific language used and the misplaced ideas this could lead to.]

From worry to action

For Archer-Nicholls, worries about the portrayal of the science were part of his decision to act. “I felt that there was an imperative for more scientists such as myself to get involved to try and help keep the messaging on point, correct misinformation and help XR stay on track,” he says. His support of the campaigning movements is largely pragmatic. “They have shown themselves to at least be able to change the public conversation faster than any other movement I have seen,” he explains. “While I don’t think they are perfect or agree with everything that is coming out of them, they are the only players in town I can see which are organising with the scale and vision needed to have a chance at preventing the worst impacts of climate change in time.”

The Cambridge-based researcher feels that the scientific community, including himself, as well as media and government, have failed to adequately communicate the urgency of the problem to the public. “This is not all the fault of the scientists, it has been made much more difficult by the spread of disinformation and climate denialism, but it has created a space into which other groups are now stepping in to up the ante,” he says. “If scientists don’t put their voices into that debate, we risk protests being fuelled by misguided understanding of the issues, which could lead to irrational decisions being made.”

Some of the science claims made by Extinction Rebellion activists go a bit over the top

Ken Caldeira

Zion Lights, UK media coordinator and national spokesperson for XR, says that science communication is a rapidly growing area with a lot of room for debate. “Of course it’s imperative that Extinction Rebellion gets the facts right, and this is a work in progress as many of the people involved are not scientists or academics, and nor should they have to be,” she says. “However, we must accept that the two aspects of this – both the rigidity of science, and the fluidity of communications – must be married together so that meaningful dialogue can take place with people who are not necessarily science-literate, to achieve the number one goal here of addressing the climate and ecological crisis that the world currently faces.”

Archer-Nicholls himself has offered advice on documents about climate science for the XR website. “I’m part of a group of scientists and communicators who review new scientific articles coming out and work out ways to make their message accessible,” he says. When he has called out XR spokespeople for presenting scientific messages badly, they have taken the criticisms on board. “I would not work with them if I thought the organisation was too dogmatic, but there does seem to be a genuine desire to learn from mistakes and present scientific knowledge as truthfully as possible.”

This has provided an unexpected shift in viewpoint for Archer-Nicholls – he’s realised how narrow a field of expertise he’d fallen into. “This process has been quite eye-opening, bringing me into contact with and forcing me to catch up on reading about a much wider picture of the climate and ecological crisis,” he says. “I feel I have developed a better grasp of the current science but also a much greater sense of the emergency situation we are in. It’s made me reflect on how the high degree of specialisation of scientists does not well equip them with the tools to understand or find solutions to a problem as big as climate change.”

I don’t think planetary and human health are things which one can be neutral about – they are surely unambiguously good

Lorraine Whitmarsh

Rowena Diamond, a PhD student at Cardiff University investigating the effects of extreme climatic events on rivers and fish in the salmon family, also believes it’s vital for scientists to get involved. “I’m interested in the actions of XR as they have a big presence and I think, if done in a correct way, they could help encompass positive change that will benefit climate and ecology,” she says. “It’s important that … the work done is based on solid research and science so that it is evidence-based, and the benefits of the actions of XR can be demonstrated.” That’s why Diamond thinks it’s useful for scientists to be involved in the movement — they will be able to provide the research needed for the group to be taken seriously. Diamond has joined XR’s community of scientists [link to Facebook page] to see if she wants to take part. She also teaches climate change in schools as part of The Brilliant Club.

School’s out

XR is not the only new kid on the block. What about another factor behind Archer-Nicholls’ decision to act – the school strikes? According to Caldeira, some have criticized the Youth Climate Strikes as naive, and there is a fair amount of naivete in the statements of some of the participants. “But a bit of idealistic naivete is perhaps a needed balance to the pessimistic realpolitik that permeates the halls and meeting rooms of many of our national governments,” he says. “We have seen in the United States, with the protests against the Vietnam War, how large numbers of people, many of them naive and idealistic, can help powerful governments to do the right thing, or at least not do as much of the wrong thing.”

“I don’t think the big protests and school strikes will change policy,” says Diamond. “I think they have been excellent for raising awareness but…I feel that if we really want to implement change, we need to be more inclusive and begin to focus on creating a global education system in which children learn about climate change and global warming, so that everyone grows up with an understanding of how the climate is changing.”

XR and the Youth Strikes are helping academics, particularly earlier career colleagues, find the courage to speak out publicly the views they hold privately

Kevin Anderson

Archer-Nicholls, who is in his early thirties, thinks Greta Thunberg has done an amazing job of articulating the injustice her generation faced. “It made me realise that my generation would the last one to have the influence to make the changes needed to prevent catastrophic climate change,” he says. “For Greta et al. it would be too late by the time they were old enough to effect change.”

Archer-Nicholls believes the school strikes hold a mirror to the ugly hypocrisies in our political response to climate change, and put a human face to those most impacted by our failure. “Their moral argument is almost impossible to combat, hence opponents end up resorting to ugly ad hominem attacks,” he says. “The school strikers also do an essential job in communicating to people across the political and social spectrum by having a direct line to many who otherwise might not pay attention, namely their parents and family.”

Chances of success?

So what are the chances of these campaigns succeeding? On this, again, there’s a range of views. It’s tricky, after all, to predict how people will act. Much harder than projecting the climate from the amount of greenhouse gases in the atmosphere is predicting how much more of these gases we’ll put there. Sometimes a single action by a single individual, like Greta Thunberg’s lone climate strike one day in August 2018, starts a cascade of consequences. Sometimes repeated actions by many professionals over many years fall on stony ground.

Some feel concerned that Extinction Rebellion could alienate some of the very people it’s trying to win onside. “Those who want to protest will,” says Diamond. “However, there are a large group of people who don’t like the large protests and I think, when talking about climate change, we really have to be careful not to exclude people. There are so many ways to engage the world about nature and ecology and climate, and I truly urge XR and non-XR scientists to find a way that suits them to communicate their passion for our planet.”

“What is perceived of as the ‘extremism’ of Extinction Rebellion could be counterproductive,” says Caldeira. “We need to reach the hearts and minds of the average working person, and the tactics and imagery used by Extinction Rebellion could come across as off-putting to these people. It is not clear to me that Extinction Rebellion is winning over Trump supporters rather than simply alienating them.”

But, Caldeira adds, there is the “Overton Window” — the range of what is considered socially acceptable debate. “By staking out a more extreme position, Extinction Rebellion may be giving more political space to people who say that the need to act on climate change is real, even if some of the fears expressed by Extinction Rebellion are unfounded.” Archer-Nicholls also namechecks the Overton window, with regards to the call for net-zero emissions by 2025. “By putting a demand out there in the public consciousness that is both direct and has a short timeframe to respond to, it moves the Overton window to include responses that might just be able to prevent climate disaster, whilst highlighting just how unambitious the targets put forward by politicians have been up to now,” he says.

Anderson appears to agree. “For the first time in many years, I see some glimmers of hope through an opening up of the debate by XR and the youth movements, leaving new space for academics, again particularly those not so locked into the prestige of seniority, to be more honest and direct about their analysis and conclusions,” he says.

Lewis feels similarly. “These strikes, protests and marches are driving climate change and biodiversity loss higher up the political agenda which is where they need to be to get new policies enacted,” he says.

As does Whitmarsh. “I think XR – along with [the] school strikers/Greta – have done a lot to raise public and political attention to climate change,” she says. “They appear also to have had some influence in the UK parliament’s decision to hold a Citizen’s Assembly on climate change. It’s unclear, though, how much their influence has been in isolation of other factors, including Greta, IPCC 1.5 [° C] report, extreme weather events, etc.”

As yet, nobody has been successful at instituting good climate policy at the scale needed, according to Caldeira. “It would be one thing to criticize a group’s strategy if you had a strategy that worked,” he says. “But none of us has a political strategy that has been able to move the needle anywhere near to where it needs to be moved. When we criticize the political strategy of others, we have to understand that we are criticizing them from the standpoint of our own failure.”

According to Archer-Nicholls, the onus is on “those scientists that think we need to reduce carbon dioxide emissions fast but don’t agree with the methods and/or demands of XR and their ilk” to find other options that can work in the time that we have and push a counterargument. “Either way, something needs to change,” he says. “Business as usual is not a viable medium-to-long term option.”

And what’s next for this researcher who has told us about his journey from scientist to XR contributor over the last year? “I have not put myself at risk of arrest and am unlikely to in the near future,” says Archer-Nicholls. He does plan to take part in a 30-minute walkout through his union (the UCU) for the climate strike on 20th September and to support the XR protests in October. “I don’t think all scientists should be going out on the front line or getting arrested,” he adds, “that is very much a personal choice and there are many good reasons not to, but it could send a powerful message if more scientists were prepared to take action.”

• Physics World would like to thank those climate scientists and others who took the time to tell us their views. These views are their own and do not necessarily represent the opinions of the institutions they work for.