Though climate change is a crisis, the population threat is even worse

Stephen Emmott
The perennial cry: we need to talk about climate change. And this week, with world
leaders in Paris, we have been. But only up to a point. For the likely impact of the
rising global population is almost entirely absent, not only from the debate about
climate change, but also from that about loss of biological diversity, food and water
security, disease, pollution and energy.

Let’s just remind ourselves of the population statistics of the past half century. In just
over half my lifetime, the world’s population has more than doubled, from 3 billion
people to now more than 7 billion. The ability to feed some of this growing
population has in no small part been a consequence of the advent of the green
revolution: that is, the industrialisation and intensification of agriculture and the
entire food production system.

Producing all this food requires a lot of water. In fact, approximately 70% of all usable
water on Earth is now used for food production. And almost 40% of the entire (ice
free) land surface of the planet is now dedicated to agriculture.

The green revolution made more food, and that made food much cheaper. As a result
of this – and increasing industrialisation and globalisation over the same period –
those of us in Europe, North America and Japan have had much more money to
spend on consumption. In fact, we embarked upon the creation of an unprecedented
consumer culture – of clothes, televisions, electronics, mobile phones, cars and
holidays.

All the food and other things we have been producing and consuming require a lot of
energy – to generate the basic materials, manufacturing, transport, use, and
disposal. As a result our use of oil, coal and gas has increased dramatically to meet
rocketing demand for energy consumption.

We are now starting to see the first signs of the impact this is having on our life
support system: Earth. Agricultural intensification is causing serious soil degradation
and depletion of groundwater in some of the most agriculturally intensive and
important areas of the planet. Land use for agriculture, urbanisation and
infrastructure (eg roads) continues to cause loss of habitat for much of the world’s
biodiversity. It is not just terrestrial ecosystems that are being degraded. Many of the
world’s marine ecosystems are being rapidly degraded by overfishing, pollution and
ocean acidification.

Demand for energy by our increasing population over the past half-century has led to
an accumulation of atmospheric carbon dioxide, the concentration of which – now
400 parts per million – has not been present on this planet for several million years.

And yes, the result of this – of all our activities and consumption – is the emerging
change in our climate apparent in the rise in global average temperature and, more
importantly, the frequency of extreme weather events: heat waves, floods, droughts.
The climate change now emerging is predominantly a consequence of the past
activities of fewer than 3 billion people; not the current activities of 7 billion of us.

Critics of the book in which I lay out this problem, Ten Billion, have sought to remind
me that, in fact, the fertility rate has been declining since the 1960s. And that we will
in any event technologise our way out of the problems we now face. And that I am
therefore being alarmist in my claims that climate change, ecosystem degradation,
land degradation, and risks to food and water security are going to get worse. I know
the global fertility rate has been dropping. Yet the global population has more than
doubled over the 50 years in which the fertility rate has been declining, and the UN
projects that there are set to be at least 10 billion of us in just a few decades.

Moreover, population growth in many counties is rising rapidly. According to the

According to the Office for National Statistics, the UK population is projected to grow
from 64 million in 2014 to 85 million in the next 80 years. That is like adding the
inhabitants of 20 new cities the size of Birmingham to the UK.

Most of the evidence points to our current “business as usual” trajectory of growth
and consumption, leading to all of our problems getting worse; potentially much
worse.

According to the US government’s Energy Information Authority, global energy

Demand for food is set to double by 2050 as a result of increasing population and
consumption per capita – especially as more people move to an increasingly meat-
based diet. So-called “rational optimists” are quick to claim that this demand will be
easily met without significant further appropriation of land for agricultural use
thanks to the ongoing “miracle” of the green revolution.

This ignores the fact that soil degradation and erosion are increasing rapidly in many
parts of the world; that many of the world’s crops are increasingly at risk from novel
(primarily) fungal pathogens; and that climate and crop models showing the number
of extreme weather events associated with predicted future climate change are
projected to have potentially devastating effects on crops in significant parts of the
world.

Indeed, there are ample reasons to be concerned that we may be heading towards
unprecedented food crises over the coming decades, with consequent extremely
deleterious risks to the health of hundreds of millions, perhaps billions, of people.
Furthermore, in many parts of the world where population is increasing rapidly,
there is a rise in the number of people living in close quarters with pigs and poultry
(not to mention the increasing consumption of “bush meat”). And as a consequence
we are greatly increasing the risk of a novel pathogen crossing the species barrier
and creating a truly terrifying global pandemic.

Remarkably, collectively, we seem to want to deny all of this: that we are the drivers
of the main problems facing us this century; and that, as we continue to grow, these
problems are set to get worse. Climate change, extreme weather events, pollution,
ecosystem degradation – the fundamental alteration of every component of the
complex system we rely upon for our survival – are due to the activities of the rising
human population.

There are no simple solutions: but leaders at the Paris summit cannot even begin to
tackle climate change unless they recognise that its parent – our increasing
population – is creating a greater looming crisis.