The Future of Life on Earth
My final lecture as Visiting Professor of Cosmology at Gresham college looks at the threats to life on Earth, with a reflection straddling cosmology, astrophysics, history and environmental issues. I argue that what we need to worry about are not the dangers that are out there, but the ones that are in here – inside ourselves. But we can also choose to become masters of our own destiny, by recognizing that the solution to the mortal dangers we face is in our own hands.
Full transcript of the lecture available here.
Excerpt
In searching for the most imminent and present danger to life on Earth, threats from space – as dramatized in many a Hollywood movie – often come to mind: asteroid strikes, supernova explosions, rogue comets, solar flares, and even the stability of empty space itself lurk in the darkness out there. But the real risk to life on our planet doesn’t stem from Newtonian orbits, nor from stellar evolution physics, nor from exotic quantum field theory calculations of Higgs vacuum stability. It is sufficient for each of us to look into a mirror: the gravest danger to the future of life on our planet it’s not out there; it’s in here. It’s us.
Mastering our own technology and ensuring that the almost god-like powers it confers serve all humankind, and all life on our planet, is never been our strong suite, it appears:
What the inventive genius of mankind as bestowed upon us in the last hundred years could have made human life care -free and happy if the development of the organizing power of man had been able to keep step with his technical advances… As it is, the hardly bought achievements of the machine age in the hands of our generation are as dangerous as a razor in the hands of a three-year old child.
These words, written by Albert Einstein ahead of the 1932 disarmament conference, are even more poignant today than they were 90 years ago – words Einstein surely pondered later in life, after the devastation brought about in Hiroshima and Nagasaki by the nuclear weapons he played a crucial role in creating – something he regretted his whole life.
In the meantime, humans have swarmed the Earth – there are close to 8 billion of us, and thanks to science and technology we lengthened our lifespan, wiped out diseases, reduced infant mortality and, for a minority of us, created a world where our almost every material whim can be satisfied at will – in a 2-hours, same-day delivery window. But the price we will pay is enormous: 40% of our world’s land is now degraded, according to a recent UN report: deforestation continues unabated, destroying irreplaceable ancient forests, while intensive farming creates salinisation, soil exhaustion, erosion. The havoc that the naked ape is wrecking on the planet is striking from space: our beautiful, blue planet is scarred in ways that would have been unimaginable a generation ago. On land, we have tilted the balance of large animals to suit our needs: farmed animals outweigh wild mammals and birds by a staggering 10 to 1. The oceans, which once seemed an inexhaustible resource, are over-exploited. After the forest and the oceans, we are now encroaching into the last remaining natural resource: space. The uncontrolled proliferation of low-Earth orbit satellites, linked in megaconstellations aiming to provide high-speed internet connection all over the globe, is creating an overcrowding that multiplies the risk of a chain reaction of collisions, which would fill low-Earth orbit with debris and potentially prevent future access to space.
In the face of the human-induced existential threat to life on Earth, some are arguing that it is time for us to flee to the stars – to build a modern-era Noah’s Ark, not out of wood on a mountaintop, but out of steel and riding on top of a rocket, to ensure survival of the human race against the metaphorical and actual flood that is coming. The idea is not new, and had been championed by the planetary scientist and science communicator Carl Sagan already, who saw it as an “insurance policy” against the not-unreasonable risk that we end up wiping ourselves out – a danger that has perhaps never been more sharply defined than today, with a tragic war raging in Europe once again. He wrote: “If our long-term survival is at stake, we have a basic responsibility to our species to venture to other worlds.”
Efforts to colonize the solar system to escape dangers on Earth are both practically and ethically misguided. Insofar as Sagan’s argument goes, I would counter that when your car starts skidding during an overtake manoeuvre on the highway, it is not the right time to call a life insurance broker – it’s the time to focus all of your efforts on regaining control of the vehicle and stave off the worst for all its passengers. Ethically, it deflects attention from the real issues by offering a false hope of salvation.
Our survey of the condition of life on Earth, and of the dangers that threaten it in the 21st century, leads to a simple conclusion. The future of life on our planet will be determined not by astrophysical phenomena in the next hundreds of thousands or millions of years, but by human decisions we will take in the coming few months and years: can we avoid nuclear incineration and a catastrophic ecological collapse?
While you have been following this lecture, the Voyager 1, launched in 1977, has silently traversed another 60,000 km of almost empty darkness in the outskirts of our solar system. Among the sounds, pictures and greetings on the Golden Record aboard Voyager, is a message by the then US president, Jimmy Carter. Written in 1977, Carter’s words ring with greater urgency today:
“Of the 200 billion stars in the Milky Way galaxy, some – perhaps many – may have inhabited planets and space faring civilizations. If one such civilization intercepts Voyager and can understand these recorded contents, here is our message: This is a present from a small distant world, a token of our sounds, our science, our images, our music, our thoughts, and our feelings. We are attempting to survive our time so we may live into yours. We hope some day, having solved the problems we face, to join a community of galactic civilizations. This record represents our hope and our determination and our goodwill in a vast and awesome universe.”
Whether or not we believe that we will one day join a “community of galactic civilizations”, it is our urgent task today to halt the mindless march of the megamachine; to repurpose its planetary power so it may serve the needs of all life on Earth; to fortify our hope and our determination not merely to survive our time, but to create a new time, free of the dangers we are inflicting upon our planet, and upon ourselves.
Should anybody come looking for Earth in a distant future, will they find a desolate planet, a cosmic tombstone marking the failed promise of the naked ape? Or will they marvel from the orbit of Jupiter at our beautiful blue dot, sparkling delicate and majestic against the darkness of space? Our actions today will determine not whether we can be “good ancestors” (as Jonas Salk once intimated), but whether we may become ancestors at all. We cannot afford to fail.
