The cause is being taken up in the corridors of power. We still need activists outside on the streets

When Mark Carney sounded a klaxon on Wednesday, the blare was unmistakable; yet it was as polite and moderately voiced an alarm as you might expect from the leader of an institution at the heart of the establishment. The governor of the Bank of England and his French counterpart warned that the global financial system faces an existential threat from climate change. Writing in the Guardian, they told companies: “Fail to adjust … fail to exist.”.

There could hardly be a greater contrast than between Mr Carney’s intervention and the thousands of Extinction Rebellion activists disrupting central London and other cities worldwide. Earlier this month they grabbed attention by supergluing themselves to the public gallery in the House of Commons, semi-naked. Mr Carney is unlikely to shed his suit for the cause. But the activists’ peaceful campaign of civil disobedience is essentially a louder, brighter, less genteel version of the same essential message: “This is an emergency.”

Who is more likely to save us? Even supporters of Extinction Rebellion have voiced doubt about specific tactics, including the intention to use mass arrests as leverage for change. But a bigger debate underlies these. It has dogged the activism from which the movement explicitly draws inspiration, including the suffragettes and the civil rights movement in the US. The question is whether real change is achieved on the streets or in the corridors of power; whether moderates or militants prevail; and whether progress is made through careful negotiation and the pursuit of acceptable compromises, or radical demands which rupture the status quo. The truth is that both are needed.

Young people have led the way. The 1.4 million who took part in last month’s school strikes have grown up learning that climate change is a fact, not a theory; it is built into their worldview. They know that they will pay the price for our inaction. They bat away excuses. That sense of impatience always pushes social change, but is all the more critical in this case, when every delay increases the risk of disaster.

But their urgency is felt more broadly. Rowan Williams, the former archbishop of Canterbury, was an early backer of Extinction Rebellion. An 80-year-old woman locked herself to the bottom of a lorry because, she said, “I refuse to leave a barren and broken world for my beautiful grandchildren.” Even inconvenienced drivers have voiced support. The shift can be seen at an institutional level too. Businesses are waking up to the costs, financial and physical, of the changes. Whether for reasons of strategy, sympathy or both, the police approach to these largely white and middle-class protesters has been unusually light-touch: hundreds of arrests, but made gradually, and with plenty of amicable chat on the sidelines.

Yet most politicians remain shockingly timid. Labour’s declaration of a climate emergency and promise of a “green industrial revolution” is encouraging; on Wednesday protesters chained themselves to a fence outside Jeremy Corbyn’s house, saying they hoped to persuade him to go further. True, voters who voice alarm at rising temperatures can be equally vocal about rising fuel prices. But the public mood is shifting. Though the climate change deniers are entrenched, and have drawn encouragement from the election and actions of Donald Trump, Brazil’s Jair Bolsonaro and others, the alarm about global warming is rising worldwide. According to Pew research, Britons now list it as the top threat to the UK. The evidence is mounting, and each grain of it is more alarming. The changes are felt, as well as read about, in the form of heatwaves, storms and other extreme weather.

There is nothing moderate about the approaching catastrophe. Adaptation to rising temperatures is inevitable; accommodation with the forces fuelling them will be disastrous. Social movements exert pressure on internal processes of change, which are inherently incremental and cautious. That parts of the establishment are now pressing for action on climate change is critical. That others are pushing from the outside is at least equally so.