"The heart is deceitful above all things,
and desperately sick;
who can understand it?" Jeremiah 17:9
Humanity is under threat. At least according to Sir
Martin Rees, one of Britain's most esteemed astronomers.
In his new book, "On the Future," Rees turns his
focus closer to home, examining the existential threats
that face humanity over the next century. From
cyberattacks to advances in biotechnology to artificial
intelligence to climate change, Rees, Britain's
astronomer royal, says we are living at a critical
juncture — one that could define how the human species
To learn more about which technologies worry him most,
his prospects for humanity's survival and why he thinks
we'll eventually enter a period of "post-human
evolution," MACH recently sat down with Rees in New York
City. This interview has been edited for clarity and
MACH: Why did you write this book now?
Rees: Over the last few years, I've had an opportunity
to interact with different technologies and more science
policy people. I was concerned that they weren't
worrying enough about some potential threats and some
potential opportunities. I thought it was good to try
and tie together my various thoughts, which I'd
expressed in lectures and articles, in a book which I
hope is fairly small and readable.
In your 2003 book, “Our Final Hour,” you gave
humanity about a 50-50 chance of surviving the 21st
century. Where do you think we stand today?
Well, we survived 18 years so far, but I do think we
will have a bumpy ride through the century. I think it's
unlikely we'll wipe ourselves out, but I do feel that
there are all kinds of threats which we are in denial
about and aren't doing enough about. I'm thinking about
climate change and the associated loss of biodiversity.
We are not urgently dealing with that. Also, we need to
contend with the fact that the world population is
getting larger. It will be at least 9 billion by
midcentury. It is going to be a big stress on resources
as well as on food production.
Apart from those two predictable trends — a warming
world and a more crowded world — there are also other
concerns. We have new technologies, which are wonderful
and powerful, but which involve risks as well. I'm
thinking of biotechnology, cybertechnology and
artificial intelligence. Biotechnology is wonderful.
It's allowed us to grow more food. It's improved health.
It's allowed us to eliminate some diseases, but it also
has a downside. It allows us to modify viruses like the
influenza virus to make it more virulent and more
transmissible. It allows us to change human beings and
animals in ways that might be ethically unacceptable.
All these new technologies are developing so fast that
we are not sure that we can really cope with them well.
It's important to get a wider audience to take these
seriously. Although these are scientific questions, the
way science is applied is really a matter for all the
public. Scientists shouldn't be the only people to
decide how science is used.
What technologies worry you most right now?
I think at the moment the main worries are
cybertechnology and biotechnology. The problem of both
cyberthreats and misuse of biotechnology is that this
can be done by just a few people. It doesn't need huge
specialist facilities, like making an atomic bomb.
There was a report by the United States Defense
Department in 2012 which said that a cyberattack on the
electricity grid on the East Coast of the U.S. was so
serious that it might, I quote, "demand a nuclear
response." That's the level of threat that we are under
These two kinds of technologies enable just a few people
to have a hugely wide-ranging and maybe even global
cascading effect. This leads to big problems of
governance because you'd like to regulate the use of
these things, but enforcing regulations worldwide is
very, very difficult. Think how hopeless it is to
enforce the drug laws globally or the tax laws globally.
To actually ensure that no one misuses these new
technologies is just as difficult. I worry that we are
going to have to minimize this risk by actions which
lead to a great tension between privacy, liberty and
Do you see ways that we can use and develop these
technologies in a responsible way?
We've got to try. We can't put the genie back in the
bottle. We've just got to make sure that we can derive
benefits and minimize risks. When I say we have a bumpy
ride, I think it is hard to imagine that there won't be
occasions when there are quite serious disruptions
caused by either error or by design using these new
You identified climate change as one of your big
worries. What do you make of the idea that we should
colonize another planet as an insurance policy against
There is the idea that we should despair and evacuate
this planet and go somewhere else. That's a dangerous
delusion. I know it's been promoted by Elon Musk and
also by my late colleague Stephen Hawking, but I think
there's no Planet B. The world's problems can't be
solved by escaping from the world. They've got to be
Although a few pioneers are going to live on Mars [in
the future], I think we are going to have to ensure that
the bulk of humanity is able to live safely and
comfortably here on this planet. It's a dangerous
delusion to think otherwise, because terraforming Mars
is much, much harder than ensuring we have a sustainable
situation here and avoid massive climate change.
But you think we’ll eventually have humans living on
I think there is a likelihood that by the end of the
century there will be a community of people living on
Mars. I think they will be people who are thrill-seeking
adventurers rather than normal people. I think they will
go there, not through a NASA program, but through one of
these private space endeavors, like Elon Musk's SpaceX
or Jeff Bezos's Blue Origin. I don't think they'll be
followed by large numbers.
These people on Mars — I think they will be important
for the far future of the 22nd century and beyond,
because they will be in an environment to which they're
ill adapted. They will have every incentive to use
bio-modification and maybe cyborg techniques — linking
to electronic machines — to adapt to their alien
environment. They will quite quickly become like a new
You talk about this prospect of “post-human
evolution” in your book. What does that mean?
It's a fundamentally new development in that it's a kind
of evolution [that] is not the Darwinian natural
selection, which over three-and-a-half billion years
have led simple life to us human beings. It will be a
version of secular intelligent design [where] we design
entities which may have greater capacity than humans.
This could happen in a few centuries rather than a few
thousand centuries, which Darwinian selection requires
in order to produce a new species. The key question is
to what extent it will be flesh-and-blood, organic
intelligence and to what extent it will be electronic.
If that happens, would we still be considered human?
This, of course, raises all kinds of philosophical
questions. People imagine that we can download human
brains one day into electronic machines. The question
is: Is that really still you? If you were told your
brain had been downloaded, would you be happy to be
destroyed? What would happen if, for instance, many
copies were made of you? Which would be your personal
Also, the question of consciousness. We know that what’s
special about us is not only that we can do all kinds of
things that demand intelligence, but we are self aware.
We have feelings and emotions. It's a big uncertainty
whether an electronic intelligence, which manifests the
same capabilities as us, will necessarily have
self-awareness. It could be that self-awareness emerges
in any entity that's especially complex and is plugged
into the external world. It could be [that] it's
something which is peculiar to hardware made of flesh
and blood, like we are, and would not be replicated by
What’s your overall message for humanity?
This century is crucial because if you're very
pessimistic, you can imagine that we will misuse
powerful technology and snuff ourselves out or foreclose
a bright, longer-term future. On the other hand, if we
use technology wisely, then it allows us to perhaps
jump-start an even more exciting kind of civilization
here on Earth and far beyond. That's why even though the
Earth has existed for 45 million centuries, and will go
on existing for many million more centuries, this
century is special because it's the one which is seeing
the transition from natural evolution to maybe
artificial evolution — whether biological or cyborg —
and also the era when, for the first time, we can escape
from this planet and perhaps start exploring others.
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emphasizing the role of the Third Temple
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has become the first country in the
world to require its public schools
nationwide to add LGBT history and
inclusion to their curriculums. Deputy
First Minister John Swinney has told
parliament that the Scottish government
will mandate all state schools to "teach
LGBTI equality and inclusion" to
different age groups across different