Good News, Bad News: Humans Will Live Another 100,000 Years
All of this doomsday talk is nonsense, says the New Scientist:
In 2008, researchers attending the Global Catastrophic Risk Conference in Oxford, UK, took part in aninformal survey of what they thought were the risks to humanity. They gave humans only a 19 per cent chance of surviving until 2100. Yet when you look more closely, such extreme pessimism is unfounded. Not only will we survive to 2100, it's overwhelmingly likely that we'll survive for at least the next 100,000 years.
Take calculations by J. Richard Gott, an astrophysicist at Princeton University. Based on 200,000 years of human existence, he estimates we will likely last anywhere from another 5100 to 7.8 million years (New Scientist, 5 September 2007, p 51).
According to most rational calculations, human beings will outsmart the various threats to their existence -- runaway technology, killer viruses, supervolcanoes, that sort of thing. There will be fewer of us, sure, if any of that stuff happens -- death toll estimates in the case of a supervocano eruption that clouds the atmosphere with deadly ash are in the billions -- but a hardy billion or two will still be writing television comedy or working the drive-thru window.
In other words, civilization will survive.
Other stuff, though, is more worrisome:
The biggest extinction threats of all come from space. Solar flares, asteroid strikes and bursts of gamma rays from supernova explosions or collapsing stars are what we really need to get through. "Every 300 million years we would expect a gamma-ray burst or a severe supernova explosion that wipes out most of the ozone layer," says Brian Thomas, an expert on intergalactic hazards based at Washburn University in Topeka, Kansas. The result would be a massive increase in harmful radiation at the Earth's surface and an increased incidence of life-threatening cancers during the decades it would take for the ozone layer to recover. It's impossible to know when such an event might occur.
Yet these things are so rare that the chance of an extinction event in the next 100,000 years is effectively zero....Which leaves the poster child of disaster movies: the asteroid strike.
This one will take some luck to avoid. Space is full of rocky debris that acts as an occasional threat to Earth. It is widely believed that the impact of a 15-kilometre-wide asteroid wiped out the dinosaurs 65 million years ago. In any 100,000 year period we can reasonably expect an impact from a 400-metre asteroid that will cause damage equivalent to 10,000 megatonnes of TNT. "Not enough to do in the whole civilisation, but certainly destroy an entire small country like France," says former astronaut Thomas Jones, who co-chairs NASA's Task Force on Planetary Defence.
So we'll lose France. Which I know may not seem like a tragedy to some of you, but as someone who loves and admires the French people and culture, I'd certainly miss it. From my basement shelter.
The real question is, for those of us who make it to 100,000 years in the future, what will we look like? What will we be like?
THERE'S a famous thought experiment about kidnapping a Cro-Magnon man, bathing and shaving him, dressing him in a suit and putting him on the New York subway. Would anybody bat an eyelid?
Probably not. Though Cro-Magnons lived about 30,000 years ago, they were to all intents and purposes modern humans. Physically they were perhaps a little more robust, but behaviourally they were indistinguishable from us, give or take the effects of thousands of years of technological progress on our lives.
Whatever we turn out to be, I'm sure we'll all be having a good laugh at this, from Al Gore in the NYTimes, about one year ago:
It would be an enormous relief if the recent attacks on the science of global warming actually indicated that we do not face an unimaginable calamity requiring large-scale, preventive measures to protect human civilization as we know it.
Apparently, we've got another 100,000 years, no problem.