The sheer pressure of our numbers, the abundance of our inventions, the blind forces of our desires and needs, appear unstoppable and are generating a heat – the hot breath of our civilisation.

How can we ever begin to restrain ourselves? We resemble a successful lichen, a ravaging bloom of algae, a mould enveloping a fruit.

We are fouling our nest, and we know we must act decisively, against our immediate inclinations. But can we agree among ourselves?

We are a clever but quarrelsome species – in our public discourses we can sound like a rookery in full throat. We are superstitious, hierarchical and self-interested, just when the moment requires us to be rational, even-handed and altruistic.

We are shaped by our history and biology to frame our plans within the short term, within the scale of a single lifetime. Now we are asked to address the wellbeing of unborn individuals we will never meet and who, contrary to the usual terms of human interaction, will not be returning the favour.

On our side we have our rationality, which finds its highest expression and formalisation in good science. And we have a talent for working together – when it suits us.

Are we at the beginning of an unprecedented era of international cooperation, or are we living in an Edwardian summer of reckless denial? Is this the beginning, or the beginning of the end?