No one sits up to listen more than I do when a 16 year old activist takes the stage, in this case the climate change campaigner Greta Thunberg speaking on Sunday to Extinction Rebellion protestors in London. After all, I was that age when, 42 years ago, I caused a stir by telling the Conservative conference to roll back socialism. Like her, I was a teenager who believed I should get involved in a vital cause, and fight for something crucial for decades ahead.

There, the similarities end. In my case, many of my contemporaries at school would have disagreed with me, and most would not have cared. In her case, huge numbers of young people support her message, and the issues she raises have become the prime political concern of activists of her generation. While I was concerned that left wing ideas were destroying opportunity, she and many more are motivated by the growing awareness that the whole of humanity is starting to devastate the planet.

It is time to recognise that these young activists are indeed focused on the right issue. The solutions presented by protestors in London or by Green parties around the world may be ill thought-out, but the analysis is now hard to gainsay. The film presented by Sir David Attenborough last week was compelling in its argument that there is perhaps only a decade left to avert the greatest threat Earth has faced in thousands of years.

Until now, scepticism about the alarming trends of climate change, and their close connection to human activity, has held some sway on the right of politics, although more in the USA and Australia than in Britain and the rest of Europe. Some of this has been natural hostility to the socialistic and highly regulatory policies preached by many campaigners. Part of it has been, sickeningly, the promotion of corporate interests at the expense of the environment. The rest has been the know-nothing attitude of populist leaders personified all too well by President Trump, who continues to maintain that what is happening to the world is some kind of elaborate hoax.

Scepticism about unproven scientific consensus can often be a healthy thing, but on the climate it has now become utterly irrational. We can measure the oceans rising, watch the coral reefs dying, see the glaciers melting and monitor the rainforests falling. It is simple chemistry that more greenhouse gases lead to higher temperatures and quite obvious who is pumping them all out. To anyone whose eyes, ears and brain are functioning properly, this part of the argument is over.