Sir Martin Rees

2012 - the year of the apocalypse? The European talked with the British Royal Astronomer Sir Martin Rees about existential risks, humanity’s bumpy ride through the 21st century, and the social responsibility of scientists.

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The European: Let’s talk about the end of life on earth. Some scientists argue that all life runs through an arc in which a time of flourishing is inevitably succeeded by sudden decline. Do you agree?

Rees: On a local perspective there are clearly ups and downs. However, astronomers have a special perspective on the far future, for reasons I can explain quickly. The stupendous timespans of the evolutionary past are now part of common culture - except, maybe, in the US Bible Belt, and in parts of the Islamic world. But most people still somehow think that humans are the culmination of the evolutionary tree. That hardly seems credible to astronomers. Our Sun formed 4.5 billion years ago, but it’s got 6 billion more before the fuel runs out. It then flares up, engulfing the inner planets. And the expanding universe will continue - perhaps forever - destined to become ever colder, ever emptier. To quote Woody Allen, eternity is very long, especially towards the end. Post-human evolution - here on Earth and far beyond - could be as prolonged as the Darwinian evolution that’s led to us - and even more wonderful. And of course evolution is even faster now than it was when it was governed by natural selection - intelligent species can use genetic technology, and perhaps machines will take over.

The European: Do you think that the end of human civilization will come from natural or anthropogenic causes?

Rees: Over most of history, threats to humanity have come from nature - disease, earthquakes, floods, and so forth. But this century is special. It’s the first where one species - ours - has Earth’s future in its hands, and could jeopardize life’s immense potential. We’ve entered a geological era called the anthropocene. The anthropocene began with the advent of thermonuclear weapons. The threat of global nuclear annihilation involving tens of thousands of bombs has been in abeyance since the Cold War ended. But later in the century, a global political realignment leading to a standoff between new superpowers, that could be handled less well or less luckily than the Cuba crisis was. But devastation could arise insidiously rather than suddenly, through unsustainable pressure on energy supplies, food, water, and other natural resources. Indeed these pressures are the prime ‘threats without enemies’ that confront us. And they’ll become ever more intractable as the population rises.

The European: Which catastrophe do you see as most likely to bring about humanity’s extinction?

Rees: I don’t think it’s likely that any catastrophe will wipe us all out. But I think humanity will have a bumpy ride throughout the 21st century. In addition to the pressures on the environment I’ve just mentioned, there are others which I describe in my recent book ‘From Here to Infinity - Scientific Horizons.’ But there’s a downside: the same technologies that promise so much also open up new vulnerabilities. For instance, global society depends on elaborate networks - electricity grids, air traffic control, international finance, just-in-time delivery and so forth. Unless these are highly resilient, their manifest benefits could be outweighed by catastrophic (albeit rare) breakdowns cascading through the system. And the threat is terror as well as error; concern about cyber-attack, by criminals or by hostile nations, is rising sharply. And there are such concerns , too, in the ‘bio’ area. Advances in genetics offer huge potential for medicine and agriculture. But already the genomes for some viruses - polio, Spanish Flu, and SARS — have been synthesized. Expertise in such techniques will become widespread, posing a manifest risk of ‘bioerror’ or ‘bioterror.’

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