Tuesday, November 1, 2011

Paul Ehrlich on population


Population growth sees myths reborn

Paul Ehrlich

November 1, 2011

The news that the human population now numbers more than 7 billion -
and the projection that it may grow to 15 billion - has caused the
re-emergence of many ancient population fallacies.

Australia is a centre of one of the most dangerous myths to infect
civilisation: that population and economic growth have no limits. The
"big Australia" fallacy is pushed by unscrupulous developers,
politicians, media moguls and their buddies, who will personally
profit from growth.

In fact, Australian population growth will promote further
destruction of the fragile environment of Australia. And it will
attack global life-support systems by adding more greenhouse
gas-emitting super-consumers to the human population.

Fortunately, most poor and middle-class Australians realise that the
growth boosters will push the costs of further overpopulation onto
them and the rest of Earth's people, while reaping the benefits for
themselves. Indeed, Australia leads all the rich countries in at
least having a debate about population and consumption, and having a
leader such as Dick Smith to galvanise it.

Let's look at some of the silliest ideas. There's the half-baked idea
that overpopulation isn't the problem - it's overconsumption. Yes,
most of humanity's environmental problems trace to too much total
consumption, but that consumption is due to population size and
per-capita consumption.

Population and consumption are no more separable in producing
environmental damage than the length and width of a rectangle can be
separated in producing its area - both are equally important.

It's also wrong to say that there is not a "population bomb" but a
"cluster bomb" of rapidly growing countries. This claim focuses on
the plight of some poor countries struggling with rapid population
growth and increasing hunger.

However, it ignores the role of rich countries in worsening that
plight and, more importantly, in contributing to the most important
population-related problems that are global: climate disruption,
toxification of the entire planet, limited fossil fuels and
increasing risk of pandemics and nuclear war.

Likewise, it is silly to suggest that the additional 2 billion people
projected to arrive by 2050 will have the same environmental impact
as the last 2 billion. No, they won't. Each person added to the
population in the future will likely, on average, cause more damage
to humanity's critical life-support systems than did the previous person.

It will be necessary to farm ever poorer lands, use more dangerous
and expensive agricultural inputs, win metals from ever-poorer ores,
drill wells deeper or tap increasingly remote or more contaminated
sources to obtain water, then spend more energy to transport that
water ever-greater distances, and so on. Of course, if humanity got
serious about protecting the environment the next 2 billion could do
less damage.

The idea that there is a big problem with ageing populations is
beloved of innumerate European politicians, but it is idiotic. The
shift of age composition towards a higher proportion of old people
who will need support is inevitable when a growing population moves
to zero population growth. But there will be a smaller proportion of
children to be supported, and it is much easier to make a 70-year-old
economically productive than a seven-year-old.

Only if the population were to grow forever could making the obvious
minor adjustments to changing population age structure be avoided.

The most widespread folly may be the idea that "healthy" economies
can grow forever at 3.5 per cent a year. It actually implies that in
20 years the capacity of Earth's environment to support us could be
roughly cut in half, and in a couple of centuries, that capacity
could be reduced to something like one-100th of today's. Perpetual
growth is the creed of the cancer cell. The human enterprise is
already too large to be sustained.

Perhaps the most dangerous fallacy of all is that the hazardous
consequences of population growth can sensibly be examined one at a
time. For example, in many discussions of the problems of feeding a
burgeoning population, the implications of climate disruption for
food production are not mentioned at all. The fact that agriculture
is utterly dependent on precipitation, patterns of which are already
changing with the rise of greenhouse gases, is rarely explained - let
alone that agriculture is one of the main emitters of those gases.

Finally, there's the idea that leaders and decision-makers understand
these fallacies. All one needs to do is listen to a political debate
among US Republican presidential candidates today, or note the
general absence of population and consumption from political
discourse, to know this is nonsense.

The debate about population and consumption should include what is
known of human evolution - which provides essential background on
human behaviour - and an understanding of what humanity is doing to
undermine its own life-support systems. If we don't change how we
treat each other and those vital systems, society almost certainly
will collapse.

Paul Ehrlich is the Bing professor of population studies at Stanford
University. This is an edited version of the Jack Beale Lecture on
the Global Environment delivered at University of NSW last night.

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