The disruptor

Roger Hallam was born in 1966 in Wales. He grew up in a farming family and spent his adult years working an organic farm in Carmarthenshire. The farm failed. Hallam attributed the failure to a succession of extreme weather events: unseasonal rains, flooding, and erratic growing conditions he believed were linked to climate change.

The loss of the farm radicalised him. Not in the tabloid sense of that word, but in the literal one: he went to the root of the problem. If farming was becoming impossible because of climate change, and if climate change was accelerating because governments refused to act, then the problem was not agricultural. It was political.

In his late forties, Hallam enrolled at King's College London. He studied social movements and civil disobedience, specifically the conditions under which non-violent protest succeeds in forcing political change. His PhD research drew heavily on the work of Erica Chenoweth, a political scientist at Harvard whose data showed that non-violent movements involving at least 3.5 per cent of a population have never failed to achieve significant political concessions.

That number, 3.5 per cent, became the core of Hallam's theory of change. His calculation was straightforward: if enough people engaged in arrestable civil disobedience, the system would be unable to process them. Police cells would overflow. Courts would be backlogged. The cost of maintaining the status quo would exceed the cost of changing it.

In January 2017, Hallam tested the theory at King's College itself. He spray-painted chalk paint on university buildings to demand divestment from fossil fuels. He was arrested, charged with criminal damage, and acquitted. Five weeks after the protest, King's College announced it would divest 14 million pounds from fossil fuel investments. Hallam took this as proof of concept.

In May 2018, Hallam co-founded Extinction Rebellion with Gail Bradbrook, a molecular biophysicist who had spent years organising around climate and ecological issues. The movement was designed around Hallam's theories: mass participation, deliberate law-breaking, and a willingness to be arrested.

XR launched publicly in October 2018 with a Declaration of Rebellion outside the UK Parliament. Within six months, it had organised the April 2019 London protests that shut down Waterloo Bridge, Oxford Circus, and Marble Arch for eleven days. More than 1,100 people were arrested. The disruption dominated British news coverage for two weeks.

The April 2019 protests achieved something measurable. The UK Parliament declared a climate emergency in May 2019, the first national legislature to do so. Whether this was a direct consequence of XR's actions or a coincidence of timing is debatable. Hallam had no doubts.

XR's structure was deliberately decentralised. Local groups could act autonomously. There was no membership fee, no formal hierarchy. Hallam's role was ideological architect rather than operational commander. He wrote the strategy documents, gave the talks, and trained activists in the theory and practice of non-violent civil disobedience.

The movement grew rapidly. By late 2019, XR had chapters in more than 60 countries. It had become the largest climate protest movement in history, measured by the number of countries involved and the scale of simultaneous actions.

Then Hallam gave an interview to a German newspaper.

In November 2019, Hallam sat down with Die Zeit, the German weekly. The interview was supposed to be about climate activism. Instead, it became the defining controversy of his public life.

Hallam discussed historical genocides in the context of his argument that the climate crisis would produce suffering on a comparable scale. He described genocides as something that has happened repeatedly throughout history. He referred to the Holocaust as, in his words, just another instance of human destructiveness. The exact phrasing was cruder than that.

The fact of the matter is, millions of people have been killed in human history due to acts of genocide. The Holocaust, yes, is just another fuckery in human history.Roger Hallam, Die Zeit, November 2019

The backlash was immediate and severe. XR Germany issued a public condemnation. Jewish organisations in Germany and the UK criticised Hallam's remarks as trivialising the Holocaust. The controversy dominated coverage of XR for weeks, overshadowing the movement's climate message entirely.

Hallam's stated intent was to argue that the death toll from climate change would rival or exceed historical atrocities, and that treating the Holocaust as uniquely incomparable made it harder to recognise the scale of the coming climate disaster. This argument, whatever its intellectual merits, landed badly in Germany, a country where Holocaust remembrance is not an abstract exercise but a constitutional and cultural obligation.

XR expelled Hallam from its formal structures in 2020. He has never retracted the remarks. He has offered what he calls clarifications of intent, maintaining that his point about the scale of climate harm was valid even if the delivery was clumsy. The clarifications have satisfied almost nobody.

The Holocaust interview is significant not because it reveals Hallam as antisemitic, a charge he denies and which the full context of his remarks does not straightforwardly support, but because it reveals something about his approach to persuasion. Hallam believes in provocation. He believes that moderate language produces moderate responses. He is willing to cause offence to force a conversation. The problem is that the conversation he forced was not about climate change. It was about him.

After his expulsion from XR, Hallam co-founded Just Stop Oil in 2022. JSO adopted a more confrontational posture than XR: fewer mass gatherings, more targeted disruption. Its tactics included throwing soup on the glass protecting a Van Gogh painting at the National Gallery, slow-walking on major roads, and climbing the gantries of the M25, London's orbital motorway.

The M25 actions in November 2022 were the most consequential. JSO activists climbed overhead gantries on multiple occasions, forcing police to stop traffic while they were removed. The disruptions caused significant delays and generated enormous public anger.

Hallam was not on the M25 gantries. He was on a Zoom call. A journalist from The Sun newspaper had gained access to a planning meeting in which Hallam and others discussed the logistics of the M25 blockade. The recording of this call became the prosecution's central evidence.

In July 2024, Judge Christopher Hehir sentenced Hallam to five years in prison for conspiracy to cause a public nuisance. Four other defendants received four-year sentences. Judge Hehir told the defendants they had crossed the line from concerned campaigners to fanatics. The trial was notable for the judge's decision to bar the defendants from mentioning climate change in their testimony, on the grounds that it was irrelevant to the charge of public nuisance.

The sentence was the longest ever imposed for non-violent protest in the United Kingdom. The UN special rapporteur on environmental defenders called it unacceptable in a democracy. Amnesty International described it as draconian.

In March 2025, the Court of Appeal heard Hallam's case. Lady Chief Justice Baroness Carr reduced the sentence from five years to four, ruling that the original term was manifestly excessive. The judgment acknowledged that some attention must be paid to conscientious motivation, even in cases involving significant public disruption.

Some attention must be paid to conscientious motivation.Baroness Carr, Lady Chief Justice, Court of Appeal judgment, March 2025, via Drill or Drop

Hallam was released from HMP Wayland on 14 August 2025 after serving approximately 13 months. In a New Statesman interview published shortly after his release, he described prison as one of the best years of his life. He said he had read more than 100 books and written an 86-page pamphlet on political strategy.

The pamphlet outlined a shift in Hallam's thinking. After years of arguing that direct action and mass civil disobedience were the only effective levers for change, he began advocating for a parallel track: electoral politics.

One of the best years of my life. I read over a hundred books. I wrote a pamphlet. I thought through the next phase.Roger Hallam, New Statesman, August 2025

Hallam emerged from prison endorsing the "Your Party" project, a political initiative associated with Jeremy Corbyn and Zarah Sultana. The project aims to build a new left-wing party outside Labour, focused on climate policy, economic redistribution, and democratic reform. Hallam's involvement suggests he now sees electoral organisation as a necessary complement to street protest, not a replacement for it but a second front.

The pivot is significant. For years, Hallam argued that conventional politics was structurally incapable of responding to the climate emergency with adequate speed. He called elections a distraction. He said the system was designed to absorb and neutralise dissent. Prison appears to have modified this position, at least partially.

Whether the electoral turn will prove more effective than the M25 gantries is an open question. Hallam's track record suggests he will pursue both approaches simultaneously, with characteristic intensity and characteristic indifference to whether anyone is comfortable with it.

There are two contradictory assessments of Roger Hallam, and both contain elements of truth.

The first is that he is an effective organiser who identified a genuine strategic gap in climate activism and filled it. Before Extinction Rebellion, there was no mass-participation civil disobedience movement focused on climate change in the UK. Before Just Stop Oil, there was no sustained campaign of economic disruption targeting fossil fuel infrastructure. Hallam created the theoretical framework and the organisational templates for both. The UK Parliament's climate emergency declaration in 2019, whatever its practical limitations, would not have happened without XR. The public visibility of climate protest in Britain increased by orders of magnitude because of movements Hallam helped build.

The second assessment is that Hallam is a liability to the cause he serves. The Holocaust interview alienated potential allies in Germany and across Europe. His confrontational public persona repels moderates. His insistence on escalation, on pushing tactics to their maximum disruptive potential, generates backlash that hardens opposition rather than building support. Polling data consistently shows that while a majority of the British public supports climate action in principle, a majority also disapproves of disruptive protest tactics.

Both of the organisations Hallam co-founded have distanced themselves from him. This is either evidence that he pushes too hard for institutions to tolerate, or evidence that institutions are designed to moderate the very radicalism that makes them effective. Hallam would argue the latter. His critics would argue the former. The movements themselves appear unsure.

What is not in dispute is the severity of the state's response to Hallam and the tactics he advocates. A five-year sentence, subsequently reduced to four, for participating in a Zoom call about a road blockade. A trial in which defendants were prohibited from explaining their motivation. These are facts that trouble civil liberties organisations regardless of their view on climate activism.

Hallam is 60 years old, recently released from prison, and pivoting toward electoral politics while showing no signs of abandoning his belief in direct action. He remains the most polarising figure in British climate activism. He is, depending on whom you ask, either the person who forced climate change onto the political agenda through sheer disruptive will, or the person who handed the movement's opponents their most effective weapon: a target.