British cosmologist and astrophysicist Martin Rees’ lecture at the Harvard School of Government, published in the New Statesman on November 26, 2014.
In today’s runaway world, we can’t aspire
to leave a monument lasting a thousand years,
but it would surely be shameful
if we persisted in policies that denied
future generations a fair inheritance
and left them with a more depleted
and more hazardous world.
I’ll start with a flashback to 1902. In that year the young H G Wells gave a celebrated lecture at the Royal Institution in London. He spoke mainly in visionary mode. “Humanity,” he proclaimed, “has come some way, and the distance we have travelled gives us some earnest of the way we have to go. All the past is but the beginning of a beginning; all that the human mind has accomplished is but the dream before the awakening.” His rather purple prose still resonates more than a hundred years later – he realised that we humans aren’t the culmination of emergent life.
But Wells wasn’t an optimist. He also highlighted the risk of global disaster: “It is impossible to show why certain things should not utterly destroy and end the human story… and make all our efforts vain… something from space, or pestilence, or some great disease of the atmosphere, some trailing cometary poison, some great emanation of vapour from the interior of the Earth, or new animals to prey on us, or some drug or wrecking madness in the mind of man.”
I quote Wells because he reflects the mix of optimism and anxiety – and of speculation and science – which I’ll try to offer in this lecture. Were he writing today he would have been elated by our expanded vision of life and the cosmos – but he’d have been even more anxious about the perils we might face. The stakes are indeed getting higher: new science offers huge opportunities, but its consequences could jeopardise our survival. Many are concerned that it is ‘running away’ so fast that neither politicians nor the lay public can assimilate or cope with it.
My own expertise is in astronomy and space technology. So you may guess that I’m kept awake at night by worry about asteroid impacts. Not so. Indeed this is one of the few threats that we can quantify. Every ten million years or so, a body a few kilometers across will hit the Earth, causing global catastrophe – there’s a few chances in a million that this is how we’ll die. But there are larger numbers of smaller asteroids that could cause regional or local devastation. A body (say) 300 metres across, if it fell into the Atlantic, would produce huge tsunamis that would devastate the East Coast of the US, as well as much of Europe. And still smaller impacts are more frequent. One in Siberia in 1908 released energy equivalent to 5 megatons.
Can we be forewarned of these impacts? The answer is yes. There are plans to survey the million potential earth-crossing asteroids bigger than 50 metres and track their orbits precisely enough to predict possible impacts. With forewarning of an impact, action could be taken to evacuate the most vulnerable areas. Even better news is that during this century we could develop the technology to protect us. A ‘nudge’, imparted a few years before the threatened impact, would only need to change an asteroid’s velocity by a millimeter per second in order to deflect its path away from the Earth.
If you calculate an insurance premium in the usual way, by multiplying probability by consequences, it turns out to be worth spending a billion dollars a year to reduce asteroid risk.
Other natural threats – earthquakes and volcanoes – are less predictable. But there’s one reassuring thing about them, as there is about asteroids: the annual risk they pose isn’t getting bigger. It’s the same for us as it was for the Neanderthals – or indeed for the dinosaurs.
In contrast, the hazards that are the focus if 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 which 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 – and the converse.)
My theme was this. Our 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.
The threat of global annihilation involving tens of thousands of H-bombs is thankfully in abeyance; there is, though, currently more risk that smaller nuclear arsenals might be used in a regional context, or even by terrorists. But we can’t rule out, later in the century, a geopolitical realignment leading to a standoff between new superpowers. So a new generation may face its own “Cuba” – and one that could be handled less well or less luckily than the 1962 crisis was.
Nuclear weapons are based on 20th century science. I’ll return later in my talk to the 21st century sciences – bio, cyber, and AI – and what they might portend.
But before that let’s focus on the potential devastation that could be wrought by human-induced environmental degradation and climate change. These threats are long-term and insidious. They stem from humanity’s ever-heavier collective ‘footprint’, which threatens to stress our finite planet’s ecology beyond sustainable limits… More…
Continue reading Reese’s riveting conclusions and insights in the New Statesman
Related discourse by Osho
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Credit to Shanti