Sir Martin Rees is the Astronomer Royal and perhaps the most influential living cosmologist. Which makes his latest book, Our Final Hour, A Scientist's Warning: How Terror, Error and Environmental Disaster Threaten Humankind's Future in this Century - On Earth and Beyond, not only credible and deeply disturbing, but an essential tool for understanding the most profound choices we are now required to make.
One the one hand, Rees is a humane man and essentially optimistic about humanity's potential, quoting H.G. Wells that "All of the past is but the beginning of a beginning; all that the human mind has accomplished is but the dream before the awakening."
One the other hand, Rees is alarmed at the many threats that could end civilization, if not all human life. Some are familiar: climate change triggering massive weather shifts (like meltwater from the Greenland ice sheet shutting down the Gulf Stream and sending Europe into a new ice age); our "sixth extinction" of species reaching a point where ecosystems unravel in cascades of failure; new plagues being unleashed through terror or scientific error. Others are less well-known: that a comet or asteroid could destroy the planet, that nanotechnology research could go awry, or that certain kinds of subatomic scientifc experiments have the potential to inadvertently create black holes, "strangelets," or other world-ending phenomena.
These are what I call the "game over" scenarios: outcomes which are so bad that the human future is extinguished. They are not cheerful reading.
Rees deserves attention, however, for one primary reason: he is not an ideologue. Though a scientist himself, he is not convinced that scientific exploration is a right, or that research or technological development should trump all other concerns. At the same time, he is well aware of both the ways in which our society is dependent on scientific progress and the difficulty of reining in research and the diffusion of powerful tools. He offers no simple answers.
How, for example, do we deal with the proliferation of technological tools which are essential to contemporary research, but can also be used to create powerful weapons?
"We are entering an era," Rees writes, "when a single person can, by one clandestine act, cause millions of deaths.... Indeed, disaster could be caused by someone who is merely incompetent rather than malign."
"I staked one thousand dollars on a bet: 'That by the year 2020 an instance of bioerror or bioterror will have killed a million people.' Of course, I fervently hope to lose this bet. But I honestly expect not to."
The problem is that the tools which could kill that million people are also the same tools used to design new medicines, explore the origins of life, fight epidemic disease, even to teach high school students biology. It doesn't take a super-villain with a secret mountain lair stocked full of cutting-edge lab equipment to produce a virus that could make things go terribly poorly for a lot of people. It takes a retail catalog and a master's degree, as was proved by several incidences of students hacking together viruses like mousepox and monkeypox out of mail-order DNA. They weren't making weapons, but making a point: don't hack genes at home, kids (but you could).
Things are already clearly out-of-control, and biological knowledge is roughly doubling every year (and with it the potential consequences of terror or error). What to do?
Rees himself is not sure. Do we install an Orwellian surveillance regime over anyone who might have access to these tools. Or do we rely on new laws banning dangerous materials and experiments and rely on a culture of openness and responsibility to enforce them? (Bill Joy, in his seminal essay "Why the future doesn't need us" argued for relinquishing the technologies that threaten us, consciously stepping back from the abyss and making due with older, safer technologies. Bruce Sterling argues a different approach in his essential "Old Genies in New Bottles" (part two here, both PDF) - that we ought to establish a global regulatory body for science, controlling all funding and guiding all research into safe and benevolent pathways. In this approach, private funding for research would be illegal and unacceptable science would wither on the vine, as "Purse strings make the best garrotes.")
Rees does us the honor of raising questions to which he doesn't have a ready answer. But he goes further, into considering implications and trade-offs, into contemplating the futures we may choose, including, finally, the ultimate choice, between wisdom and extinction:
"Humanity is more at risk than at any earlier phase in its history. The wider cosmos has a potential future that could even be infinite. Will those vast expanses of time be filled with life, or as empty as Earth's first sterile oceans? The choice may depend on us, this century."