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Controlling the future -

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50 years ago the population of the world was less than 3 billion. Now it's more than double that
number. The projection is 9 billion by 2050. Climate change provides a challenge in providing food
for the entire world's people. The current rate of extinctions is 1,000 times faster than what has
occurred in the past. Biodiversity is being destroyed. Martin Rees says we're in denial about some
risks. Top of the list is climate change. Science, says Rees is the global culture. Rees says the
present century may be a defining moment as we are the first species to hold the future of the
planet in its hands.

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Robyn Williams: 350 years ago The Royal Society of London was formed. Yes, that's one of the main
scientific anniversaries for 2010. A group of clever men were all together in Oxford to keep away
from the plague, and decided that the new natural philosophies had to have a unifying force. And so
this great society was established. Christopher Wren, Robert Boyle and other enlightened fellows
were there in the beginning. Then our own Sir Joseph Banks returned from Australia a century later
and was president for 42 years. And now the main in charge is Lord Rees, Martin Rees, Astronomer
Royal and Master of Trinity College in Cambridge. And he's the ideal fellow to kick off The Science
Show in this celebratory year. Here he is in Cambridge talking about the future.

Martin Rees: Ladies and gentlemen, I'd like to take as my text the famous closing words of The
Origin of Species. I'm myself an astronomer and astronomers aim to probe back before Darwin's
simple beginning, to set our solar system in a cosmic context to understand how its, and the atoms
it's made of, came into existence.

For astronomers an iconic figure ranking with Darwin is Isaac Newton, another great Cambridge
alumnus. But I'm delighted that it's Darwin and not Newton who we're celebrating. Newton might have
beaten Darwin on an IQ test, but he was a deeply unattractive character! Solitary and obsessive
when young; vindictive and vain in his later years. But he was of course the first to understand
how the planets go cycling on in their orbits. And he must have thought about space travel. He
calculated that the cannonball would need to go at 18,000 miles an hour in order to go in a
trajectory that led to an orbit. And the first object actually to reach orbit was of course
Sputnik, which went up in 1957. Just 12 years later, 40 years ago, Neil Armstrong's one small step
gave us an image that's imprinted on the memories of all of us who are now middle aged.

But another image from that era has become just as iconic - the photo taken by the Apollo 8
astronauts portraying the delicate biosphere of our earth contrasting with the sterile moonscape in
the foreground. And let me offer a cosmic vignette, as it were, inspired by this image. Suppose
some alien species had been watching our planet for its entire history. What would they have seen?
Over nearly all that time, 45 million centuries, change was very gradual. Continents drifted, the
ice cover waxed and waned, species emerged, evolved and became extinct. But then suddenly the pace
of change accelerated, as humans came on the scene and grew in numbers and impact. Agriculture
transformed vegetation and forests, the carbon dioxide in the atmosphere began to rise due to the
burning of fossil fuels.

And something else unprecedented happened, small projectiles launched from the planet's surface,
escaped the biosphere completely. Some went into orbit around the earth, some journeyed to the moon
and beyond. Well could the hypothetical aliens have predicted this runaway spasm occupying less
than a millionth of the elapsed time? And if they continued to keep watch, what might they witness
in this century? What does the future hold?

One trend we can predict with confidence is that by mid-century there will, barring global
catastrophe, be more people on the world than today. 50 years ago, the world population was below 3
billion. It's more than doubled since then to 6.7 billion today, and it's projected to reach 9
billion by 2050. By then it will be in Asia, not Europe nor the US, where the world's physical and
intellectual capitals are concentrated.

In most countries, fertility's fallen below replacement level, and we know the social trends that
lead to this demographic transition, declining infant mortality, availability of contractive
devices, women's education and so forth. And if that transition quickly extended to all countries,
then the global population could gradually decline after 2050, a development that would surely be
benign. But the demographic transition hasn't occurred in Africa, where there could be a billion
more people in 2050 than there are today.

In 1950, Europe had three times Africa's population. In 2050, Africa will have three time's
Europe's population. And it's there that the bottom billion are increasingly concentrated, trapped
in poverty. Over 200 years ago, Mao first famously argued that population would rise until limited
by food shortages. His gloomy prognosis has been forestalled by advancing technology, the green
revolution and so forth. But he could be tragically vindicated in Africa.

A second green revolution may be needed to forestall tragedy, and massive migration from Africa
into Europe motivated by desperation is a real threat. The challenge of feeding earth's growing
population is aggravated by climate change. And a second firm prediction about 2050 is that the
world will then be warmer than today. The consequent shifts in weather patterns and rising sea
levels impact most grievously on those least able to adapt, and on contrary to themselves
contributed minimally to global CO2 emissions.

What should make us specially anxious is the significant probability of triggering a grave and
irreversible global trend. Rising sea levels due to the melting of Greenland's icecap, runaway
release of methane in a tundra and so forth. The science is intricate, but it's a doddle compared
to the politics and economics, for two reasons. Unlike most familiar pollution, the impact of CO2
isn't local. Emissions from the UK and Australia have the same global effects. Any effective
polluter pays principle must therefore be international.

And a second feature of global warming is the time lag. The effects of enhanced CO2 take decades to
manifest themselves fully. History will surely judge us harshly if we discount too heavily what
might happen when our grandchildren grow old. But socio-biologists might tell us that this cerebral
reaction is contrary to the deeply ingrained focus on those close to us, which evolution has
selected for.

The target as passed by the G8 plus five nations is to reduce global emissions to half the 1990
level. This target corresponds to two tonnes of CO2 per person per year on the planet. For
comparison, the current American level is 20, the current European level is 10, the Chinese level
is 5.5 and the Indian 1.5. So it's urgent to develop clean and more efficient technology soon
enough that Asian per capita emissions never need rise to ours, and ours go down to converge
towards theirs.

Some pessimists argue that the international community should as a fallback contemplate a plan B,
being fatalistic about the rise in CO2 but intervening to combat its warming effects, by for
instance putting iron filings in the ocean or aerosols in the atmosphere, or even vast sunshades in
space. Such geo-engineering, even if feasible, wouldn't solve climate change. It would at best buy
time and might have adverse unintended consequences. However, whether we like it or not, we humans
are willy nilly remaking the biosphere. Indeed we're severely ravaging it already by changes in
land use and deforestation that are far too fast for species to adapt to. There have been five
great extinctions in the past, we are causing a sixth. The extinction rate is a thousand times
higher than normal, and increasing. And to quote Bob May, we are destroying the book of life before
we've read it.

Biodiversity, manifested in forests, coral reefs and all earth's other ecosystems, is often claimed
as a crucial component of human wellbeing and economic growth. It manifestly is. We're clearly
harmed if fish stocks dwindle to extinction, and massive destructions of rainforests would
accelerate global warming, and to our plants whose gene pool might be useful to us. But for
environmentalists, these instrumental and anthropocentric arguments aren't the only compelling
ones. For them, preserving the richness of our biosphere has value in its own right over and above
what it means to us as humans. Some years ago I wrote a book which I entitled Our Final Century?
The publishers took away the question mark! And the American publishers retitled the book as Our
Final Hour. Americans want instant gratification and perhaps the reverse too!

The book addressed the issues I've just discussed and some other I'll briefly mention. Most of us
have a confused attitude to risk. We fret about traces of carcinogens in food, a one in a million
chance of being killed in a train crash and so forth. But we're in denial about others that should
loom much larger. For instance, infectious diseases are a resurgent hazard. A global pandemic could
kill tens of millions and cost many trillions of dollars. If we apply to pandemics the same prudent
analysis that leads us to buy insurance, multiplying probability by consequence, we'd surely
conclude that measures to alleviate this kind of extreme event need higher priority. Effective
prevention and early warning has to be a fully international endeavour. Whether or not a pandemic
gets global grip may depend on how quickly a Vietnamese poultry farmer can diagnose or report any
strange sickness.

In the coming decades, there could be a kind of arms race between ever improving preventative
measures and the growing virulence of the pathogens that could plague us, the latter augmented
perhaps by the risks of bio-error or bio-terror. And a spate of epidemics is aggravated by rapid
air travel plus the huge concentration of people in mega cities with fragile infrastructures.

And the nature of risk has changed. If a boiler explodes, it's horrible, but there's an upper limit
to just how horrible. But in our interconnected world, there are new risks whose consequences could
be so devastating and so dispersed that even a tiny probability is disquieting. We're all
precariously dependent on elaborate networks, electricity grids, air traffic control, the internet,
just in time delivery and so forth. And it's crucial to optimise the resilience of all these
systems. In a future era, a vast individual empowerment by bio-cyber nanotechnology, even one
malign act could be too many, and the global village will have its village idiots.

We're kidding ourselves if we think that tactical expertise is always allied with balanced
rationality. It can be combined with fanaticism, not just a traditional fundamentalism we're so
mindful of today, but new age irrationalities. I'm thinking of the Raelians, violent animal rights
campaigner, and people with those mindsets.

Let me now inject some optimism! The good news. Obviously healthcare is improving at a global
level. Indeed it's been a welcome rebalancing of effort. Traditionally the focus was on diseases of
the rich; cardiovascular diseases and cancer. But tropical diseases are now receiving more
attention and that's thanks substantially to the impetus of the Bill and Melinda Gates Foundation.
And mindful of where Bill Gates got his money, let's recall that the silicon chip was perhaps the
most transformative single invention of the last century. It's allowed miniaturisation, spawned
mobile reach of mobile phones and internet, promoted economic growth while being sparing of energy
and resources. Indeed these advances amaze us by their rapidity. iPhones would have seemed magic 30
years ago. NASA at the time of the Apollo program had less computer power than in an iPhone, even
than in a washing machine today.

If advances continue at the same pace, computers will by 2050 achieve human capabilities. Of course
in some respects they already have. The most basic pocket calculator can hugely surpass us in
arithmetic. IBM's Deep Blue beat Kasparov, the world chess champion. But not even the most advanced
robots can recognise and handle the pieces on a real chessboard as adeptly as a five year old
child. There's a long way to go before interactive human level robotic intelligence is achieved.
But when that does happen, everyone's lifestyle and work pattern will surely be transformed.

For scientists, incidentally, some kind of mental prosthetics may become essential. A unified
theory of physics or a theory of consciousness might be beyond the power of unaided human brains,
just as surely as quantum mechanics would flummox a chimpanzee. Another speculation, a real
wildcard in population projections, is that the human lifespan could be greatly extended. Indeed
some Americans worry that they'll die before this nirvana is reached, bequeath their bodies to be
frozen on their death. If they can't afford the whole body, they want their head frozen. They hope
that some future generations will resurrect them or download their brains into a computer. Well for
my part, I'd sooner end my days in an English churchyard, rather than a Californian refrigerator!

But flaky futurologists aren't always wrong. I tell students they derive more stimulus from first
rate science fiction than from second rate science. And we should keep our minds open or at least
ajar to whacky seeming concepts. Before this century's end, novel mind enhancing drugs, genetics
and cyborg techniques may start to alter human beings themselves. Evolution will proceed, not just
at the pace of Darwinian selection, but on a much shorter timescale of technological change. The
post-human era may beckon sooner than we think. But one is surely on firm grounds in one further
forecast. There will be an ever widening gulf between what science enables us to do and what
applications it's prudent or ethical actually to do. More doors that science could open, but which
are best kept closed.

Decisions on science's application, whether to energy, GM technology, stem cells, mind enhancing
drugs or whatever, must be based on the best scientific advice. But strategic, economic, social and
ethical ramifications enter as well. And here scientists have no special credentials; that's why
science education should be universal. Science is changing the world in this century. The response
to the problems it raises should not be a go slow on science, but faster and redirected research.
But as well as science changing the world, science is part of our culture. Indeed it's the one
truly global culture common to all faiths and all nations. It's a cultural deprivation not to be
aware of how some still mysterious event nearly 14 billion years ago led to the emergence of atoms,
galaxies, stars and planets, and how here on earth life began and Darwinian selection led to
creatures able to ponder their origins.

Robyn Williams: You're listening to Lord Rees, President of the Royal Society of London, speaking
at the Darwin Festival in Cambridge. This is The Science Show.

Martin Rees: And I want to spend my last ten minutes pondering what might lie beyond our earth.
Since Apollo, manned space flight has stagnated. Robotic probes have however gone to most of the
planets of our solar system, beaming back pictures of varied and distinctive worlds. A European
robotic probe landed on Titan, Saturn's giant moon, a couple of years ago. The river channels are
rivers of liquid methane. The lake is a methane lake, the temperature is minus 180 degrees

Well, within the next 50 years, robotic probes will have explored in detail all the bodies of the
solar system. Will they find signs of life? Evidence for even the most primitive life, provided
especially that we could show it as an independent origin, would be a momentous discovery. But the
prospects of finding a propitious habitat are surely hugely enlarged if we widen our gaze beyond
the solar system, to others stars far beyond the reach of any probe we can now conceive. We've
learn enough about the stars to understand them. Stars and atoms are much simpler than the simplest
biological organism, like an insect. We see places where new stars are still forming today, the
Eagle Nebular, and we see stars dying, some elegantly like the sun will in six billion years, some
more violently in supernova explosions. Stars are fuelled by nuclear fusion. They forge from
pristine hydrogen all the elements of the periodic table. And they fling the debris back into
space. Galaxies like ours are really like ecological systems where gas is being recycled. And our
entire galaxy is really part of our environment in an intimate sense. For us to understand
ourselves, we must understand the atoms we're made of, but we must also understand the stars far
away in our Milky Way that made those atoms.

In this cosmic or galactic perspective, how unusual is our earth? We've recently learnt something
that makes the night sky much more interesting. The stars aren't just twinkling points of light;
many are orbited by retinues of planets, just like the sun is. Planets can't be directly seen
around other stars, but many have been inferred indirectly. There are two ways of inferring them;
one is that if a planet is orbiting a star, then both actually orbit around a common centre of
mass, and you can detect the little wobble in the motion of the star. Another way is to watch a
star very carefully and detect a slight dimming if a planet moves across in front of it and blocks
out some of its light. By techniques like this, hundreds of extra solar planets have already been
inferred. But these are mainly giant planets, objects the size of Jupiter and Saturn, the giants of
our solar system.

In seeking evidence for cosmic life, we'd be specially interested in possible twins of our earth,
planets the same size as ours orbiting other sun-like stars on orbits with temperatures such that
water neither boils nor stays frozen. And actually imaging earth-like planets rather than just
detecting their shadow moving across a star is a task for the future.

To understand this challenge, suppose an alien astronomer with a powerful telescope was looking at
our solar system from say 30 light years away, the distance of a nearby star. The sun would look
like an ordinary star and our planet would seem in Carl Sagan's nice phrase, 'a pale blue dot',
very close to its star, our sun, that outshines it by many billions. But if the aliens watched our
earth, they could learn quite a bit. The shade of blue will be slightly different depending on
whether the Pacific Ocean or the landmass of Eurasia was facing them. So the aliens could infer
that there were continents, the length of the day, the seasons and the climate. By analysing the
faint reflected light they could infer that we had a biosphere.

Within 20 years, instruments like this array in space or this huge projected telescope on the
ground will, I fully expect, allow us to detect huge numbers of planets the same size as our earth,
orbiting other sun-like stars, and draw the kind of inferences I just indicated.

But will there be life or not? We still know too little about how life began here on earth to be
able to say whether alien life is likely or unlikely. Even if simple life is common, it's of course
a separate question whether it's likely to evolve into anything we might recognise as intelligent.
Indeed I gather among evolutionists, there's still debate about what would happen if evolution were
re-ran on the earth, would we end up with an intelligent species?

Well as you know, there are ongoing privately funded searches for extraterrestrial intelligence,
the so-called SETI program. And perhaps this program will one day detect a signal that's clearly
artificial. Even if it's very boring, a list of prime numbers or the digits of pi, it would carry
the momentous message that concepts of logic and physics, if not consciousness, aren't limited to
the hardware in human skulls. But if we did detect anything like that, then there would I suppose
be some shared culture, even if the aliens were on planet Zog and had seven tentacles, they'd be
made of the same kind of atoms as us. They'd gaze out, if they had eyes, at the same cosmos, they'd
trace their origins back to the same big bang. But of course any aliens would be at the very least
tens of light years away, so if we get a signal, there's time to send a measured response, no scope
for snappy repartee!

Well, we may learn in the coming decades not only more about how life began on the earth, but more
importantly whether biological evolution is unique to our home planet, or whether Darwin's writ
runs in the wider universe. If advanced life is rare, if SETI searches are destined to fail, we
might feel lonely. But were that the outcome, we would get a boost to our cosmic self-esteem,
because tiny though our earth is, it could still be special, even in the context of our galaxy.
Moreover, this outcome, finding ourselves alone, wouldn't mean that life would forever be a trivial
afterthought in an overwhelmingly sterile cosmos. And that's because of another realisation which
astronomers can offer to evolutionists, and that's the awareness of an immense future. The
stupendous time spans of the evolutionary past are now of course part of common understanding
outside creationist circles. But most people, while accepting that, still somehow think we humans
are towards the culmination of the evolutionary tree. And that hardly seems credible to me as an

Our sun formed four and a half billion years ago, but it's got six billion years before the fuel
runs out. It then flares up, engulfing the inner planets, and vaporising whatever remains on earth.
And the expanding universe will continue much longer, perhaps forever, destined to become ever
colder, ever emptier. To quote Woody Allen, 'eternity is very long, especially towards the end'.
Any creature witnessing the sun's demise six billion years hence here on earth or far beyond won't
be human. They'll be as different from us as we are from a bug. This quote reminds us that Darwin
himself realised this, that we are not the culmination. And post-human evolution here on earth and
far beyond could be as prolonged as a Darwinian evolution that's led to us and even more wonderful.

However, my concluding message is this. Even in this concertinaed timeline, extending billions of
years into the future as well into the past, the present century may be a defining moment. It's the
first in our planet's history when one species, ours, has earth's future in its hands, and could
not only jeopardise itself but foreclose life's immense potential. So this 'pale blue dot' in the
cosmos is a special place and we are its stewards at a pivotal era. Thank you very much.


Martin Rees

Professor of Cosmology and Astrophysics Master of Trinity College University of Cambridge Cambridge


Robyn Williams


David Fisher

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