How Can we Persuade Climate Alarmists to Acknowledge There Are Two Sides to This Argument?
We need to get better at disagreeing about climate change, writes Cambridge professor Mike Hulme
This piece by Professor Mike Hulme is the third in a series of 12 articles challenging climate change orthodoxy commissioned by Professor Gwythian Prins. We will be publishing the articles at a rate of one a week over the next 12 weeks (read the first article here and the second article here). The hope is that they can be collected into a book for Sixth Formers and university students.
In October 2023, the new Vice-Chancellor of the University of Cambridge, the American psychology professor Deborah Prentice, delivered her first Annual Address to Senate House. Her address highlighted the imperative for university students to learn to “disagree well” about difficult subjects and for universities to facilitate this learning. Prentice announced her intention to moderate a series of open ‘dialogues’ at Cambridge, in which experts challenge each other on pressing issues of the day.
Prentice’s initiative was no doubt prompted by the lively public debate in the UK around free speech, cancel culture and academic freedom. It is a pressing issue within university life at the present time. In some instances, students and academics are being bullied into tacitly accepting viewpoint orthodoxies, fearful for their reputations and of being castigated for expressing contrarian views. A slew of books have recently appeared challenging the chilling climate of self-righteous orthodoxy that has emerged in recent years, among them Charlan Nemeth’s In Defense of Troublemakers: The Power of Dissent in Life and Business; Andrew Doyle’s The New Puritans: How the Religion of Social Justice Captured the Western World; and Umut Ozkirimli’s Cancelled: The Left Way Back from Woke.
I have been arguing that we need to ‘disagree well’ for longer than the Vice-Chancellor of Cambridge. In 2009, I published my first climate book, Why We Disagree About Climate Change, which argued that unless we isolate and clarify the specific reasons why our attitudes and responses to climate change differ so markedly, we cannot truly claim to be taking the issue seriously. In the book’s dedication, I noted that disagreement is always – or at least should always be – a form of learning. Without hearing from those with whom we disagree, and without engaging them in debate and argument, we exist merely inside a partisan echo chamber rather than as part of a functioning democracy.
I believe this to be truer still of the politics of climate change than it was 16 years ago. There is no single correct way of interpreting and dealing with the risks and challenges of climate. Those who claim otherwise, and seek to suppress public and political debate because in their view stopping climate change matters more than respecting democracy, are dangerous ideologues with tunnel vision. This is the thrust of my more recent book, Climate Change Isn’t Everything: Liberating Climate Politics from Alarmism.
On Disagreement and Democracy
Disagreeing with others – whether on matters great or small, public or private – is part of the essence of what it is to be human. We each see the world differently, weigh evidence differently and hold different attitudes to risk, danger, justice and injustice. Giving space for such disagreements to be voiced and heard – and tolerating the dissenters – is a foundational principle of democracy. Provoked by US Vice-President J D Vance’s recent public criticism of Europe’s fragile commitment to free speech, the Economist conceded that Europe really does have a problem and asked: “What, practically, should Europeans do? They should start by returning to the old liberal ideas that noisy disagreement is better than enforced silence and that people should tolerate one another’s views.” A free and open society needs heterodox thinkers to be heard without fear of censorship or marginalisation. As the late Jerome Kagan, professor of developmental psychology at Harvard, noted:
Every democracy needs an opposition party to prevent the one temporarily in power from becoming despotic. And every society needs a cohort of intellectuals to check the dominance of a single perspective when its ideological hand becomes too heavy.
Not just in politics, but in science too. The lifeblood of science is to question, to doubt and to challenge. Criticism fulfils a necessary and positive function in science, but unlike a literary critic a scientific critic has no independent status. As Jacob Bronowski once noted, whereas literary critics carry status in their own right, to be a scientific critic is to be a scientist. Scientific dissidents may not be popular with those who think they know the truth, but they are necessary if science is to command respect from the wider public. It is not that every heterodox thinker is correct; it is rather that, just as with a free and open society, science needs heterodox thinkers. Their arguments should be heard without suppression; groupthink, censorship and a thought police have no place in science.
Reducing Arguments to Labels
The easiest way to avoid hard thinking on any complex problem is to silence those who disagree with you. There are different ways this might be done, but all three adopt an ad hominem approach to winning an argument. You might call into question the integrity or sincerity of your critic; you might damn their views by associating them with discredited fellow-travellers; or you might dismiss their views as unworthy of consideration by attaching derogatory labels to their position.
Of these, the last is the most subtle, and this divide-and-rule tactic has been widely deployed in the climate change debate. Using a pejorative label such as ‘climate change denier’ to characterise the views of those with whom you disagree serves to isolate, exclude and dismiss their claims as unworthy of discussion. Once a pejorative label is attached to them, arguments can be waved away without further engagement. An emphasis on labels accentuates division and diverts attention from getting to the root of the disagreement – which is essential for public debate and understanding of a complex issue.
But this practice of ‘marking the card’ of those deemed to ‘deny’ climate science proved too narrowly drawn for those pursuing this tactic. So it is now possible to reach for an array of alliterative labels to call out those who, it is claimed, seek to undermine or slow efforts to address the risks of climate change. One can choose from the following lexicon of additional ‘d-words’: climate ‘delayers’, ‘dissemblers’, ‘deceivers’, ‘downplayers’, ‘dividers’, ‘deflectors’, ‘doomers’ and ‘distractors’.
This strategy has been taken to its next logical step on the HotAir website, commissioned and operated by Tortoise Media, the new owners of the Observer. HotAir ingests a large digital corpus of so-called ‘contrarian’ claims about climate change which have been pre-classified using a deep-learning AI model. This model imposes a fivefold scheme with further sub-categories: ‘global warming is not happening’, ‘human greenhouse gases are not causing global warming’, ‘climate impacts are not bad’, ‘climate solutions won’t work’ and ‘the climate movement/science is unreliable’. HotAir then classifies these textual fragments – speech acts emanating from individuals, organisations or websites – and ‘marks’ them as propagating either climate denial, climate delay or political coercion.
But this approach seriously misleads audiences by conflating very different reasons for disagreement over climate change. Criticising certain aspects of climate science is a quite different matter from criticising certain policies or climate solutions – a distinction those advocating the new lexicon of ‘d-words’ refuse to acknowledge. Claims that ‘mountain glaciers aren’t retreating’ or that ‘atmospheric carbon dioxide concentration is not rising’ are, for example, entirely different from claims that ‘green jobs don’t work’, ‘nuclear energy is good’ or ‘the media is alarmist’.
These latter claims cannot be determined to be scientifically correct or incorrect – either because the evidence is conflicting, the standards by which we judge them are values-based, or because they are partially true and partially false. Some media reporting of climate change is undoubtedly alarmist; nuclear energy is for many part of a desirable and necessary energy mix; and whether green jobs ‘work’ depends on what that criterion means, for whom and over what time period. Creating a catch-all definition of ‘climate delay’ blurs the distinction between very different types of argument and risks proscribing legitimate public debate about climate policies.
Legitimate Epistemic Uncertainty
The examples above reveal the problems of policing what can or cannot be contested in respect of climate policies. But the same divide-and-rule tactic is often applied to what is or is not known scientifically about the changing climate. In science, the boundaries between “truth” and “untruth” are not easily drawn. The distinctions between Johann Wolfgang von Goethe’s “conditioned certainty”, Bertrand Russell’s “moderate scepticism” and Robert Merton’s “organised scepticism” are often fuzzy. Where those boundaries lie should certainly not be determined by those external to the actual practices of science and scientific assessment; established scientific practice, processes and norms are their own policing mechanisms.
It is quite legitimate, for example, to read carefully the latest IPCC reports and identify what is known in climate science to varying levels of confidence. The Met Office’s ‘climate change questions’ website does a reasonable job of this. What is not legitimate is to extrapolate from a high-level claim such as ‘97% of scientists believe that human activities are changing the climate’ and attach a similar level of consensus to every claim made about human influence on climate. Still less should scientists succumb to the lure of the noble lie. There are many facets of a changing global climate where science does not speak with one voice, where we still ‘see through a glass darkly’. Scientists must be free to say so without the chilling effect of being labelled a climate ‘doubter’, ‘delayer’ or ‘distractor’. Recent examples from the peer-reviewed literature where scientific opinion remains widely divergent include: the impact of climate change on the south Asian monsoon; the effectiveness and risks of solar geoengineering technologies; the necessity of carbon capture; the future behaviour of hurricanes; and the scientific credibility of extreme weather attribution studies.
Conclusion
Climate change is real and serious, but it is not everything. Aiming to deliver largely arbitrary global temperature targets, or pursuing Net Zero emissions by a given date, foregrounds crude aggregated metrics that reduce the dimensionality of the climate change problem. They narrow the political field of vision and can too easily lead to policy missteps. Sloganeering around such metrics must not foreclose political debate over the effectiveness and desirability of specific policies which, while they may help reduce climate risks, may simultaneously undermine or foreclose other legitimate policy goals.
Writing in a different time and a different context, the late liberal-internationalist newspaper editor David Astor offered a trenchant defence of free speech that is worth rehearsing, whatever one’s position in the climate debate. Among his private papers was one titled ‘Memo on the Soul of a Paper’, which summarised the beliefs that permeated his long editorship of the Observer between 1948 and 1975. On Astor’s watch, the paper’s personality was shaped by people drawn together more by being ‘anti-fascist’ – that is, anti-Hitler – than by anything else. His beliefs are lucidly set out in the following passage, extracted from the Memo:
Treating opponents respectfully; trying to understand people and to explain them to each other; valuing differences; not exaggerating your own case; avoiding over-dramatisation or enjoyment of the sensational; practising moral courage, particularly daring to stand up to ridicule, and showing respect for that [courage] in others; discouraging herd thinking, particularly among those ‘on our side’; challenging taboos and legends, particularly those ‘our sort’ of reader usually accepts; deliberately cultivating doubt and scepticism, but not cynicism; practising self-criticism – as liberals, as internationalists, as journalists – as well as dishing it out to everyone else.
The new inheritors of Astor’s legacy at the Observer – Tortoise Media, with their HotAir website – would do well to read his Memo in full and apply it wholeheartedly to their reporting of climate change.
Mike Hulme is Professor of Human Geography in the Department of Geography, University of Cambridge, and a Fellow of Pembroke College, Cambridge. He was formerly Professor of Climate and Culture at King’s College London (2013–2017) and of Climate Change in the School of Environmental Sciences at the University of East Anglia.


