Environmentalists may get off on climate porn, but most people just turn away. 'If it was really so bad, they'd do something,' says one colleague, without specifying who 'they' are. The human tendency to convince yourself that everything is OK, because no one else is worried, is deeply ingrained.

I know that most men, including those at ease with problems of the greatest complexity, can seldom accept even the simplest and most obvious truth if it be such as would oblige them to admit the falsity of conclusions which they have delighted in explaining to colleagues, which they have proudly taught to others, and which they have woven, thread by thread, into the fabric of their lives.

The members of the department became like the Athenians who, according to the Apostle Paul, 'spent their time in nothing else, but either to tell or to hear some new thing.' Anyone who thought he had a bright idea rushed out to try it out on a colleague. Groups of two or more could be seen every day in offices, before blackboards or even in corridors, arguing vehemently about these 'brain storms.' It is doubtful whether any paper ever emerged for publication that had not run the gauntlet of such criticism. The whole department thus became far greater than the sum of its individual members.

The scientist has to take 95 per cent of his subject on trust. He has to because he can't possibly do all the experiments, therefore he has to take on trust the experiments all his colleagues and predecessors have done. Whereas a mathematician doesn't have to take anything on trust. Any theorem that's proved, he doesn't believe it, really, until he goes through the proof himself, and therefore he knows his whole subject from scratch. He's absolutely 100 per cent certain of it. And that gives him an extraordinary conviction of certainty, and an arrogance that scientists don't have.