http://www.belfasttelegraph.co.uk/featu ... 715156.ece
This planet ain't big enough for the 6,500,000,000 of us
Wednesday, June 27, 2007
Behind the climate crisis lies a global issue that no one wants to
tackle: do we need radical plans to reduce the world's population?
Chris Rapley sparks the debate
What do the following have in common: the carbon dioxide content of
the atmosphere, Earth's average temperature and the size of the human
population? Answer: each was, for a long period of Earth's history,
held in a state of equilibrium. Whether it's the burning of fossil
fuels versus the rate at which plants absorb carbon, or the heat
absorbed from sunshine versus the heat reflected back into space, or
global birth rates versus death rates - each is governed by the
difference between an inflow and an outflow, and even small imbalances
can have large effects. At present, all of these three are out of
balance as a result of human actions. And each of these imbalances is
creating a major problem.
Second question: how do these three differ? Answer: human carbon
emissions and climate change are big issues at the top of the news
agenda. And rightly so, since they pose a substantial threat. But
population growth is almost entirely ignored. Which is odd, since it
is at the root of the environmental crisis, and it represents a danger
to health and socioeconomic development.
The statistics are quite remarkable. For most of the two million years
of human history, the population was less than a quarter of a million.
The advent of agriculture led to a sustained increase, but it took
thousands of years, until 1800, before the planet was host to a
billion humans. Since then growth has accelerated - we hit 2 billion
in 1930, 3 billion in 1960, 4 billion in 1975, 5 billion in 1987 and 6
billion in 1999. Today's grand total is estimated to be 6.5 billion,
with a growth rate of 80 million each year.
To what can we attribute such a dramatic rise? Impressive increases in
the food supply have played a part, but the underlying driver has been
the shift from an "organic" society, in which energy was drawn from
the wind, water, beasts of burden (including humans) and wood, to a
fossil fuel-based world in which most of our energy is obtained by
burning coal, oil and gas. This transition has fuelled the changes in
quality of life associated with modern technology, especially the
major advances in hygiene and medicine. Although unevenly distributed,
these bounties have seen life expectancy double and a corresponding
reduction in mortality rates.
But success in reducing mortality has not been matched by a lowering
of the birth rate - and this has resulted in the dramatic increase in
the human stock. As noted by Malthus, who at the end of the 18th
century was the first to foresee the problems of population growth,
such growth can accelerate rapidly since every individual has the
capacity to produce many offspring, each of whom can in turn produce
many more, and the process will only cease when something happens to
bring birth rate and death rate once more into balance.
In fact, the overall growth rate of the world's population hit a peak
of about 2 per cent per year in the late Sixties and has since fallen
to 1.3 per cent. Although the timing and magnitude of the changes have
been different in different parts of the world, the pattern has
followed the so-called "demographic transition". Initially both
mortality and birth rates are high, with the population stable. As
living standards rise and health conditions improve, the mortality
rate decreases. The resulting difference between the numbers of births
and deaths causes the population to increase. Eventually, the birth
rate decreases until a new balance is achieved and the population
again stabilises, but at a new and higher level.
Demographers offer two possible explanations for the decline in birth
rate, suggesting that it is an inherent tendency of societies to find
an equilibrium between births and deaths, with the lag simply being
the time taken for the change in mortality rate to be recognised.
Alternatively, it is attributed to the same general driving forces
that caused the decline in mortality, such as improvements in medical
practice and technology, in this case birth control.
So where do we stand today? Worldwide, the birth rate is about six per
second, and the death rate stands at three per second. UN figures
foresee numbers levelling out at a point when we have between 8 and 10
billion humans by 2050 - that's roughly a 50 per cent increase on
today's figure.
This is not comforting news. Even at current levels, the World Health
Organisation reports that more than three billion people are
malnourished. And although food availability continues to grow, per
capita grain availability has been declining since the Eighties.
Technology may continue to push back the limits, but 50 per cent of
plants and animals are already harvested for our use, creating a huge
impact on our partner species and the world's ecosystems. And it is
the airborne waste from our energy production that is driving climate
change.
Yet, even at a geo-political level, population control is rarely
discussed. Today, however, marks the publication of a new report on
population by the United Nations Environment Programme. Perhaps this
could be the spur we need.
If debate is started, some will say that we need to stop the world's
population booming, and to do so most urgently where the birth rates
are highest - the developing world. Others may argue that it is in the
developed world, where the impact of individuals is highest, that we
should concentrate efforts. A third view is to ignore population and
to focus on human consumption.
Programmes that seek actively to reduce birth rates find that three
conditions must be met. First, birth control must be within the scope
of conscious choice. Second, there must be real advantages to having a
smaller family - if no provision is made for peoples' old age, the
incentive is to have more children. Third, the means of control must
be available - but also to be socially acceptable, and combined with
education and emancipation of girls and women.
The human multitude has become a force at the planetary scale.
Collectively, our exploitation of the world's resources has already
reached a level that, according to the World Wildlife Fund, could only
be sustained on a planet 25 per cent larger than our own.
Confronted with this state of affairs, there is much discussion about
how to respond to human impacts on the planet and especially on how to
reduce human carbon emissions. Various technical fixes and changes in
behaviour are proposed, the former generally having price tags of
order trillions of dollars. Spread over several decades, these are
arguably affordable, and to be preferred to the environmental damage
and economic collapse which may otherwise occur.
But by avoiding a fraction of the projected population increase, the
emissions savings could be significant and would be at a cost, based
on UN experience of reproductive health programmes, that would be as
little as one-thousandth of the technological fixes. The reality is
that while the footprint of each individual cannot be reduced to zero,
the absence of an individual does do so.
Although I'm now the director of the British Antarctic Survey, I was
previously executive director of the International Geosphere-Biosphere
programme, looking at the chemistry and biology of how Earth works as
a system. About 18 months ago, I wrote an article for the BBC Green
Room website in which I raised the issues: "So if we believe that the
size of the human footprint is a serious problem (and there is much
evidence for this) then a rational view would be that along with a
raft of measures to reduce the footprint per person, the issue of
population management must be addressed.
"In practice, of course, it is a bombshell of a topic, with profound
and emotive issues of ethics, morality, equity and practicability. So
controversial is the subject, that it has become the Cinderella of the
great sustainability debate - rarely visible in public, or even in
private. In interdisciplinary meetings addressing how the planet
functions as an integrated whole, demographers and population
specialists are usually notable by their absence. Rare, indeed, are
the opportunities for religious leaders, philosophers, moralists,
policy-makers, politicians and the global public to debate the
trajectory of the world's human population in the context of its
stress on the Earth system, and to decide what might be done."
The response from around the world was strong and positive - along the
lines of "at last, this issue has been raised". But after that initial
burst of enthusiasm, I find that little has changed. This is a pity,
since as time passes, so our ability to leave the world in a better
state is reduced. Today's report from the UN provides an opportunity
to raise the debate once again. For the sake of future generations, I
hope that others will this time take up the challenge.
