Humans: the real threat to life on Earth

Computational scientist Stephen Emmott argues that if population levels continue to rise at the current rate, our grandchildren will see the Earth plunged into an unprecedented environmental crisis. Our cleverness, inventiveness, and activities are now the drivers of every global problem we face. The situation we're in right now is an emergency – an unprecedented planetary emergency.

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The Observer
Climate change
Humans: the real threat to life on
Earth
If population levels continue to rise at the current rate, our grandchildren will
see the Earth plunged into an unprecedented environmental crisis, argues
computational scientist Stephen Emmott in this extract from his book Ten
Billion
Stephen Emmott
Sun 30 Jun 2013 00.05 BSTFirst published on Sun 30 Jun 2013 00.05 BST
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The global population is projected to pass 10 billion this century. Photograph:
Getty
Earth is home to millions of species. Just one dominates it. Us. Our
cleverness, our inventiveness and our activities have modified almost every
part of our planet. In fact, we are having a profound impact on it. Indeed, our
cleverness, our inventiveness and our activities are now the drivers of every
global problem we face. And every one of these problems is accelerating as we
continue to grow towards a global population of 10 billion. In fact, I believe we
can rightly call the situation we're in right now an emergency – an
unprecedented planetary emergency.
We humans emerged as a species about 200,000 years ago. In geological time,
that is really incredibly recent. Just 10,000 years ago, there were one million
of us. By 1800, just over 200 years ago, there were 1 billion of us. By 1960, 50
years ago, there were 3 billion of us. There are now over 7 billion of us. By
2050, your children, or your children's children, will be living on a planet with
at least 9 billion other people. Some time towards the end of this century,
there will be at least 10 billion of us. Possibly more.
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We got to where we are now through a number of civilisation- and society-
shaping "events", most notably the agricultural revolution, the scientific
revolution, the industrial revolution and – in the West – the public-health
revolution. By 1980, there were 4 billion of us on the planet. Just 10 years
later, in 1990, there were 5 billion of us. By this point initial signs of the
consequences of our growth were starting to show. Not the least of these was
on water. Our demand for water – not just the water we drank but the water
we needed for food production and to make all the stuff we were consuming –
was going through the roof. But something was starting to happen to water.
Back in 1984, journalists reported from Ethiopia about a famine of biblical
proportions caused by widespread drought. Unusual drought, and unusual
flooding, was increasing everywhere: Australia, Asia, the US, Europe. Water, a
vital resource we had thought of as abundant, was now suddenly something
that had the potential to be scarce.

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By 2000 there were 6 billion of us. It was becoming clear to the world's
scientific community that the accumulation of CO2, methane and other
greenhouse gases in the atmosphere – as a result of increasing agriculture,
land use and the production, processing and transportation of everything we
were consuming – was changing the climate. And that, as a result, we had a
serious problem on our hands; 1998 had been the warmest year on record. The
10 warmest years on record have occurred since 1998.
We hear the term "climate" every day, so it is worth thinking about what we
actually mean by it. Obviously, "climate" is not the same as weather. The
climate is one of the Earth's fundamental life support systems, one that
determines whether or not we humans are able to live on this planet. It is
generated by four components: the atmosphere (the air we breathe); the
hydrosphere (the planet's water); the cryosphere (the ice sheets and glaciers);
the biosphere (the planet's plants and animals). By now, our activities had
started to modify every one of these components.
Our emissions of CO2 modify our atmosphere. Our increasing water use had
started to modify our hydrosphere. Rising atmospheric and sea-surface
temperature had started to modify the cryosphere, most notably in the
unexpected shrinking of the Arctic and Greenland ice sheets. Our increasing
use of land, for agriculture, cities, roads, mining – as well as all the pollution

we were creating – had started to modify our biosphere. Or, to put it another
way: we had started to change our climate.
There are now more than 7 billion of us on Earth. As our numbers continue to
grow, we continue to increase our need for far more water, far more food, far
more land, far more transport and far more energy. As a result, we are
accelerating the rate at which we're changing our climate. In fact, our activitie
are not only completely interconnected with but now also interact with, the
complex system we live on: Earth. It is important to understand how all this is
connected.
Let's take one important, yet little known, aspect of increasing water use:
"hidden water". Hidden water is water used to produce things we consume but
typically do not think of as containing water. Such things include chicken,
beef, cotton, cars, chocolate and mobile phones. For example: it takes around
3,000 litres of water to produce a burger. In 2012 around five billion burgers
were consumed in the UK alone. That's 15 trillion litres of water – on burgers.
Just in the UK. Something like 14 billion burgers were consumed in the United
States in 2012. That's around 42 trillion litres of water. To produce burgers in
the US. In one year. It takes around 9,000 litres of water to produce a chicken.
In the UK alone we consumed around one billion chickens in 2012. It takes
around 27,000 litres of water to produce one kilogram of chocolate. That's
roughly 2,700 litres of water per bar of chocolate. This should surely be
something to think about while you're curled up on the sofa eating it in your
pyjamas.
But I have bad news about pyjamas. Because I'm afraid your cotton pyjamas
take 9,000 litres of water to produce. And it takes 100 litres of water to
produce a cup of coffee. And that's before any water has actually been added t
your coffee. We probably drank about 20 billion cups of coffee last year in the
UK. And – irony of ironies – it takes something like four litres of water to
produce a one-litre plastic bottle of water. Last year, in the UK alone, we
bought, drank and threw away nine billion plastic water bottles. That is
36 billion litres of water, used completely unnecessarily. Water wasted to
produce bottles – for water. And it takes around 72,000 litres of water to
produce one of the 'chips' that typically powers your laptop, Sat Nav, phone,
iPad and your car. There were over two billion such chips produced in 2012.
That is at least 145 trillion litres of water. On semiconductor chips. In short,
we're consuming water, like food, at a rate that is completely unsustainable.
Demand for land for food is going to double – at least – by 2050, and triple –
at least – by the end of this century. This means that pressure to clear many of

the world's remaining tropical rainforests for human use is going to intensify
every decade, because this is predominantly the only available land that is left
for expanding agriculture at scale. Unless Siberia thaws out before we finish
deforestation. By 2050, 1bn hectares of land is likely to be cleared to meet
rising food demands from a growing population. This is an area greater than
the US. And accompanying this will be three gigatons per year extra
CO2emissions.If Siberia does thaw out before we finish our deforestation, it
would result in a vast amount of new land being available for agriculture, as
well as opening up a very rich source of minerals, metals, oil and gas. In the
process this would almost certainly completely change global geopolitics.
Siberia thawing would turn Russia into a remarkable economic and political
force this century because of its newly uncovered mineral, agricultural and
energy resources. It would also inevitably be accompanied by vast stores of
methane – currently sealed under the Siberian permafrost tundra – being
released, greatly accelerating our climate problem even further.
Amazon rainforest smoulders after being cleared for cattle pasture in Brazil.
Photograph: Michael Nichols/Getty Images
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Meanwhile, another 3 billion people are going to need somewhere to live. By
2050, 70% of us are going to be living in cities. This century will see the rapid
expansion of cities, as well as the emergence of entirely new cities that do not
yet exist. It's worth mentioning that of the 19 Brazilian cities that have doubled
in population in the past decade, 10 are in the Amazon. All this is going to use
yet more land.
We currently have no known means of being able to feed 10 billion of us at our
current rate of consumption and with our current agricultural system. Indeed,
simply to feed ourselves in the next 40 years, we will need to produce more
food than the entire agricultural output of the past 10,000 years combined.
Yet food productivity is set to decline, possibly very sharply, over the coming
decades due to: climate change; soil degradation and desertification – both of

which are increasing rapidly in many parts of the world; and water stress. By
the end of this century, large parts of the planet will not have any usable water
At the same time, the global shipping and airline sectors are projected to
continue to expand rapidly every year, transporting more of us, and more of
the stuff we want to consume, around the planet year on year. That is going to
cause enormous problems for us in terms of more CO2 emissions, more black
carbon, and more pollution from mining and processing to make all this stuff.
But think about this. In transporting us and our stuff all over the planet, we
are also creating a highly efficient network for the global spread of potentially
catastrophic diseases. There was a global pandemic just 95 years ago – the
Spanish flu pandemic, which is now estimated to have killed up to 100 million
people. And that's before one of our more questionable innovations – the
budget airline – was invented. The combination of millions of people
travelling around the world every day, plus millions more people living in
extremely close proximity to pigs and poultry – often in the same room,
making a new virus jumping the species barrier more likely – means we are
increasing, significantly, the probability of a new global pandemic. So no
wonder then that epidemiologists increasingly agree that a new global
pandemic is now a matter of "when" not "if".
We are going to have to triple – at least – energy production by the end of this
century to meet expected demand. To meet that demand, we will need to
build, roughly speaking, something like: 1,800 of the world's largest dams, or
23,000 nuclear power stations, 14m wind turbines, 36bn solar panels, or just
keep going with predominantly oil, coal and gas – and build the 36,000 new
power stations that means we will need.Our existing oil, coal and gas reserves
alone are worth trillions of dollars. Are governments and the world's major oil,
coal and gas companies – some of the most influential corporations on Earth
– really going to decide to leave the money in the ground, as demand for
energy increases relentlessly? I doubt it.
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Meanwhile the emerging climate problem is on an entirely different scale. The
problem is that we may well be heading towards a number of critical "tipping
points" in the global climate system. There is a politically agreed global target
– driven by the Intergovernmental Panel on Climate Change (IPCC) – to limit
the global average temperature rise to 2C. The rationale for this target is that
rise above 2C carries a significant risk of catastrophic climate change that
would almost certainly lead to irreversible planetary "tipping points", caused

by events such as the melting of the Greenland ice shelf, the release of frozen
methane deposits from Arctic tundra, or dieback of the Amazon. In fact, the
first two are happening now – at below the 2C threshold.
As for the third, we're not waiting for climate change to do this: we're doing it
right now through deforestation. And recent research shows that we look
certain to be heading for a larger rise in global average temperatures than 2C
– a far larger rise. It is now very likely that we are looking at a future global
average rise of 4C – and we can't rule out a rise of 6C. This will be absolutely
catastrophic. It will lead to runaway climate change, capable of tipping the
planet into an entirely different state, rapidly. Earth will become a hellhole. In
the decades along the way, we will witness unprecedented extremes in
weather, fires, floods, heatwaves, loss of crops and forests, water stress and
catastrophic sea-level rises. Large parts of Africa will become permanent
disaster areas. The Amazon could be turned into savannah or even desert. And
the entire agricultural system will be faced with an unprecedented threat.
More "fortunate" countries, such as the UK, the US and most of Europe, may
well look like something approaching militarised countries, with heavily
defended border controls designed to prevent millions of people from
entering, people who are on the move because their own country is no longer
habitable, or has insufficient water or food, or is experiencing conflict over
increasingly scarce resources. These people will be "climate migrants". The
term "climate migrants" is one we will increasingly have to get used to. Indeed
anyone who thinks that the emerging global state of affairs does not have grea
potential for civil and international conflict is deluding themselves. It is no
coincidence that almost every scientific conference that I go to about climate
change now has a new type of attendee: the military.
Every which way you look at it, a planet of 10 billion looks like a nightmare.
What, then, are our options?
The only solution left to us is to change our behaviour, radically and globally,
on every level. In short, we urgently need to consume less. A lot less. Radically
less. And we need to conserve more. A lot more. To accomplish such a radical
change in behaviour would also need radical government action. But as far as
this kind of change is concerned, politicians are currently part of the problem,
not part of the solution, because the decisions that need to be taken to
implement significant behaviour change inevitably make politicians very
unpopular – as they are all too aware.

So what politicians have opted for instead is failed diplomacy. For example:
The UN Framework Convention on Climate Change, whose job it has been for
20 years to ensure the stabilisation of greenhouse gases in the Earth's
atmosphere: Failed. The UN Convention to Combat Desertification, whose job
it's been for 20 years to stop land degrading and becoming desert: Failed. The
Convention on Biological Diversity, whose job it's been for 20 years to reduce
the rate of biodiversity loss: Failed. Those are only three examples of failed
global initiatives. The list is a depressingly long one. And the way governments
justify this level of inaction is by exploiting public opinion and scientific
uncertainty. It used to be a case of, "We need to wait for science to prove
climate change is happening". This is now beyond doubt. So now it's, "We
need to wait for scientists to be able to tell us what the impact will be and the
costs". And, "We need to wait for public opinion to get behind action". But
climate models will never be free from uncertainties. And as for public
opinion, politicians feel remarkably free to ignore it when it suits them – wars,
bankers' bonuses and healthcare reforms, to give just three examples.
What politicians and governments say about their commitment to tackling
climate change is completely different from what they are doing about it.
What about business? In 2008 a group of highly respected economists and
scientists led by Pavan Sukhdev, then a senior Deutsche Bank economist,
conducted an authoritative economic analysis of the value of biodiversity.
Their conclusion? The cost of the business activities of the world's 3,000
largest corporations in loss or damage to nature and the environment now
stands at $2.2tn per year. And rising. These costs will have to be paid for in
the future. By your children and your grandchildren. To quote Sukhdev: "The
rules of business urgently need to be changed, so corporations compete on the
basis of innovation, resource conservation and satisfaction of multiple
stakeholder demands, rather than on the basis of who is most effective in
influencing government regulation, avoiding taxes and obtaining subsidies for
harmful activities to maximise the return for shareholders." Do I think that
will happen? No. What about us?
I confess I used to find it amusing, but I am now sick of reading in the
weekend papers about some celebrity saying, "I gave up my 4×4 and now I've
bought a Prius. Aren't I doing my bit for the environment?" They are not doing
their bit for the environment. But it's not their fault. The fact is that they – we
– are not being well informed. And that's part of the problem. We're not
getting the information we need. The scale and the nature of the problem is
simply not being communicated to us. And when we are advised to do
something, it barely makes a dent in the problem. Here are some of the

changes we've been asked to make recently, by celebrities who like to
pronounce on this sort of thing, and by governments, who should know better
than to give out this kind of nonsense as 'solutions': Switch off your mobile
phone charger; wee in the shower (my favourite); buy an electric car (no,
don't); use two sheets of loo roll rather than three. All of these are token
gestures that miss the fundamental fact that the scale and nature of the
problems we face are immense, unprecedented and possibly unsolvable.
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The behavioural changes that are required of us are so fundamental that no
one wants to make them. What are they? We need to consume less. A lot less.
Less food, less energy, less stuff. Fewer cars, electric cars, cotton T-shirts,
laptops, mobile phone upgrades. Far fewer.And here it is worth pointing out
that "we" refers to the people who live in the west and the north of the globe.
There are currently almost 3 billion people in the world who urgently need to
consume more: more water, more food, more energy. Saying "Don't have
children" is utterly ridiculous. It contradicts every genetically coded piece of
information we contain, and one of the most important (and fun) impulses we
have. That said, the worst thing we can continue to do – globally – is have
children at the current rate. If the current global rate of reproduction
continues, by the end of this century there will not be 10 billion of us.
According to the United Nations, Zambia's population is projected to increase
by 941% by the end of this century. The population of Nigeria is projected to
grow by 349% – to 730 million people.
Afghanistan by 242%.
Democratic Republic of Congo 213%.
Gambia by 242%.
Guatemala by 369%.
Iraq by 344%.
Kenya by 284%.
Liberia by 300%.
Malawi by 741%.
Mali by 408%.

Niger by 766%.
Somalia by 663%.
Uganda by 396%.
Yemen by 299%.
Even the United States' population is projected to grow by 54% by 2100, from
315 million in 2012 to 478 million. I do just want to point out that if the
current global rate of reproduction continues, by the end of this century there
will not be 10 billion of us – there will be 28 billion of us.
Where does this leave us? Let's look at it like this. If we discovered
tomorrow that there was an asteroid on a collision course with Earth and –
because physics is a fairly simple science – we were able to calculate that it
was going to hit Earth on 3 June 2072, and we knew that its impact was going
to wipe out 70% of all life on Earth, governments worldwide would marshal
the entire planet into unprecedented action. Every scientist, engineer,
university and business would be enlisted: half to find a way of stopping it, the
other half to find a way for our species to survive and rebuild if the first option
proved unsuccessful. We are in almost precisely that situation now, except
that there isn't a specific date and there isn't an asteroid. The problem is us.
Why are we not doing more about the situation we're in – given the scale of
the problem and the urgency needed – I simply cannot understand. We're
spending €8bn at Cern to discover evidence of a particle called the Higgs
boson, which may or may not eventually explain mass and provide a partial
thumbs-up for the standard model of particle physics. And Cern's physicists
are keen to tell us it is the biggest, most important experiment on Earth. It
isn't. The biggest and most important experiment on Earth is the one we're all
conducting, right now, on Earth itself. Only an idiot would deny that there is a
limit to how many people our Earth can support. The question is, is it
seven billion (our current population), 10 billion or 28 billion? I think we've
already gone past it. Well past it.
Science is essentially organised scepticism. I spend my life trying to prove my
work wrong or look for alternative explanations for my results. It's called the
Popperian condition of falsifiability. I hope I'm wrong. But the science points
to my not being wrong. We can rightly call the situation we're in an
unprecedented emergency. We urgently need to do – and I mean actually do –
something radical to avert a global catastrophe. But I don't think we will. I
think we're fucked. I asked one of the most rational, brightest scientists I know

– a scientist working in this area, a young scientist, a scientist in my lab – if
there was just one thing he had to do about the situation we face, what would
it be? His reply? "Teach my son how to use a gun."
This is an edited extract from Ten Billion, by Stephen Emmott (Penguin,
£6.99)
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