After putting $100m into Covid research, the billionaire is taking on the climate crisis. And first he has some bones to pick with his fellow campaigners...

• Read an exclusive extract from Gates’ new book

Bill Gates appears via video conference – Microsoft Teams, not Zoom, obviously – from his office in Seattle, a large space with floor-to-ceiling windows overlooking Lake Washington. It’s a gloomy day outside and Gates is, somewhat eccentrically, positioned a long way from the camera, behind a large, kidney-shaped desk; his communications manager sits off to one side. If one had to stage, for the purposes of symbolism, a tableau of a man for whom a distance of 3,000 miles between callers still constitutes too intimate a setting, it might be this. “As a way to start,” says Gates’ aide, “would it be helpful for Bill to make a couple of comments about why he wrote his new book?” It is helpful, and I’m not ungrateful, but this is not how interviews typically commence.

There is an urge towards deference, when speaking to Gates, which attends few other people of commensurate fame. Celebrity is one thing, but wealth – true, former-richest-man-in-the-world wealth – is something else entirely; one has a sense of being granted an audience with the Great Man, a fact made more surreal by his famously muted persona. The 65-year-old has the lofty, mildly longsuffering air of a man accustomed to being the smartest guy in the room, leavened by wry amusement and interrupted, on the evidence of past interviews, by the occasional peevish outburst – most memorably in 2014, when Jeremy Paxman questioned him about Microsoft’s alleged tax avoidance. (“I think that’s about as incorrect a characterisation of anything I’ve ever heard,” he said, practically squirming in his seat with annoyance.)