Here’s an interesting question. As the world’s population
inexorably rises, will the living ever outnumber the dead? Has it already
happened? No, it’s not even close. It’s impossible to be sure how many human
beings have lived and died on planet Earth, but one good estimate is 100
billion. It might well be more than that, but it’s probably not a lot less.
Compare that to the current population of the earth, which
reached seven billion at the beginning of this decade. Unless we humans move
into space and start breeding very fast, the living are never going to
outnumber the dead. There just isn’t room on the planet. But seven billion is
still a lot of people. Far too big to grasp mentally: a billion is a thousand
times more than a million, so the difference between the two is like the
difference between £1 and £1,000. Seven billion – 7,000,000,000 – is a very big
It’s taken a long time to get here. For most of human
existence, stretching back thousands of years to our origins in Africa, our
population stayed in the low millions. At one time it was far less: there seems
to have been a demographic bottleneck in Africa when the population shrank
dramatically before slowly recovering. Was there a natural disaster like a
mega-volcano or an asteroid-strike? If there was, we were lucky to survive it:
we had all our eggs in one basket – Africa – and we nearly lost them all.
Natural disasters are still a big threat, but we keep our
eggs in more baskets now, because we aren’t living on just one continent any
more. So perhaps the biggest threat we face is ourselves. In the 1960s and
’70s, many commentators were very worried about population growth. There were
real fears that natural resources would run out and that food supplies wouldn’t
keep pace with the demands placed on them. The commentators were too
pessimistic: there was an agricultural revolution that delivered ever more food
with ever greater efficiency. Today you should say that we have too much food.
One of the world’s biggest health-problems is obesity, even in relatively poor
countries like Mexico.
Too many people still go hungry in regions like Africa, but
the problem there is distributing food, not producing it. And despite poverty
in Africa and the Middle East, the birth-rate is still very high. In some
Western nations like Italy, it’s fallen below replacement level: the average
number of children is less than the number required to keep the population at
the same level, neither growing nor shrinking. The “Baby Boom” that followed the
Second World War is a distant memory.
But the Boom has an echo. If one period of history sees more
births than those periods that go before and after, something will happen
later: a period in which the death rate rises, as the baby-boomers reach the end
of their lives. That is what is happening now: the death of David Bowie didn’t
just mean the end of his remarkable musical career. It also signalled that his
baby-boomer generation are nearing the end of their lives. Life-expectancy has
risen steadily in the past century, but just as some commentators were too
pessimistic about population growth in the 1960s and ’70s, some others were too
optimistic about scientific and medical advances.
Some forecasters thought that man would land on Mars before
the end of the twentieth century. It didn’t happen. They also thought that
average life-spans would be well over a century by 2010. That hasn’t happened
either. Even in Japan, the longest-lived of all nations, the average woman dies
before her ninetieth birthday. Medicine still has a long way to go before it
can fulfil the dreams of science-fiction.