A new lecture that Martin Rees recently gave at Harvard’s Program on Science, Technology and Society, has now been published online in The New Statesman. In his talk, Martin Rees encouraged scientists and policymakers to consider hazards that might curtail the future development of human civilisation. Here is a short excerpt:
In contrast, the hazards that are the focus of this talk are those that humans themselves engender – and they now loom far larger. And in discussing them I’m straying far from my ‘comfort zone’ of expertise. So I comment as a ‘citizen scientist’, and as a worried member of the human race. I’ll skate over a range of topics, in the hope of being controversial enough to provoke discussion.
Ten years ago I wrote a book that I entitled Our Final Century? My publisher deleted the question-mark. The American publishers changed the title to Our Final Hour (Americans seek instant gratification).
My theme was this. Earth is 45 million centuries old. But this century is the first when one species – ours – can determine the biosphere’s fate. I didn’t think we’d wipe ourselves out. But I did think we’d be lucky to avoid devastating setbacks. That’s because of unsustainable anthropogenic stresses to ecosystems, because there are more of us (world population is higher) and we’re all more demanding of resources. And – most important of all – because we’re empowered by new technology, which exposes us to novel vulnerabilities.
And we’ve had one lucky escape already.
At any time in the Cold War era – when armament levels escalated beyond all reason – the superpowers could have stumbled towards Armageddon through muddle and miscalculation. During the Cuba crisis I and my fellow-students participated anxiously in vigils and demonstrations. But we would have been even more scared had we then realised just how close we were to catastrophe. Kennedy was later quoted as having said at one stage that the odds were ‘between one in three and evens’. And only when he was long retired did Robert McNamara state frankly that “[w]e came within a hairbreadth of nuclear war without realizing it. It’s no credit to us that we escaped – Khrushchev and Kennedy were lucky as well as wise.” Be that as it may, we were surely at far greater hazard from nuclear catastrophe than from anything nature could do. Indeed the annual risk of thermonuclear destruction during the Cold War was about 10,000 times higher than from asteroid impact.
It is now conventionally asserted that nuclear deterrence worked. In a sense, it did. But that doesn’t mean it was a wise policy. If you play Russian roulette with one or two bullets in the barrel, you are more likely to survive than not, but the stakes would need to be astonishing high – or the value you place on your life inordinately low – for this to seem a wise gamble. But we were dragooned into just such a gamble throughout the Cold War era. It would be interesting to know what level of risk other leaders thought they were exposing us to, and what odds most European citizens would have accepted, if they’d been asked to give informed consent. For my part, I would not have chosen to risk a one in three – or even one in six – chance of a disaster that would have killed hundreds of millions and shattered the historic fabric of all our cities, even if the alternative were certain Soviet dominance of Western Europe. And of course the devastating consequences of thermonuclear war would have spread far beyond the countries that faced a direct threat especially if a nuclear winter were triggered…