That escalates every existential threat – nuclear war, global warming, and mass structural violence

Most people, and certainly most politicians, don’t spend much time or emotional energy thinking about whether human life on this planet will still exist in one hundred years’ time, or what efforts might need to be made right now if we and our descendants are to avoid extinction.

More Covid-scale pandemics, and the increasingly obvious reality of global warming, are both now being seen – though still not universally – as serious risks demanding serious policy response. They may prove to be game changers. But, here as with other potentially huge man-made risks, complacency generally prevails. Since the end of the Cold War, it has been hard to energise policymakers and publics anywhere in the world about the risk of annihilation by nuclear weapons – and even harder to alarm anyone but a handful of afficionados about developments in artificial intelligence amounting to a measurable threat to our very existence.

Andrew Leigh, as so often, sees things differently. With the same extraordinary energy and polymathic reach – more than a little alarming to us lesser mortals – that he has brought to publishing eight books on multiple subjects in the less than twelve years that he has been a member of the Australian Parliament, not to mention running marathons and devoting quality time to his young family, he has now published a wake-up call on the reality of global existential risks that should be hard for any of us to ignore.

Leigh’s focus in What’s the Worst That Could Happen? is not on ‘natural’ risks such as asteroid impact, super-volcanic eruption, or stellar explosion, which, though beloved by some catastrophists, he not unreasonably assesses as being either so remote or so beyond human capacity to avoid, or both, that they are not worth worrying about. His book is rather about the anthropogenic risks posed particularly by out-of-control artificial intelligence, engineered pandemics, climate change, and nuclear war, which, Leigh suggests, together add up to a one in six chance that within a century all human life will go the way of dodos and dinosaurs.

He relies for this extraordinary figure on the Australian Oxford philosopher Toby Ord’s highly praised analysis in The Precipice: Existential risk and the future of humanity (Hachette, 2021), which assesses these individual risks of extinction as ranging in magnitude from one in 1,000 (nuclear war and climate change) to one in ten (out-of-control artificial intelligence). Leigh’s book (like Ord’s, which Robert Sparrow reviewed in the December 2020 issue of ABR) would benefit from more detailed explanation of the methodology behind both these individual judgements – involving, essentially, knowledgeable guesstimates rather than anything more robustly objective – and especially the arithmetic (not obvious to the uninitiated reader) which enables them to be distilled, collectively, into odds of one in six for human extinction. But these figures are certainly not incredible, and they should concentrate our minds.

Where Leigh breaks new and very interesting ground, going beyond anything in Ord’s work, is in drawing a link between existential risk and extreme politics. His book is as much about the anatomy, and dangers, of populism – of both the left and right – as an incubator and accelerator of these risks as it about the risks themselves. The basic storyline, and he develops it very persuasively, is that ‘tackling long-term threats requires four things: strong science, effective institutions, global engagement, and a sense of cooperation and order. Populists are anti-intellectual, anti-institutional, anti-international and anti-irenic.’ (‘Irenic’, he helpfully reminds us, means to strive for peace and consensus.) In short, ‘we should no more expect populists to be good crisis leaders than we should expect jockeys to be good at basketball’. And it gets worse: if populists coming to power within democratic systems succeed in become authoritarian demagogues – a recurring phenomenon from Hitler to Hun Sen, and with the Trumps, Orbáns, Erdoğans, Bolsonaros, and perhaps Modis of this world giving us plenty to currently worry about – then populism itself becomes a dangerously destructive force.