It¡¯s official. There are now 7 billion people on earth
and projection show will top 8 billion just twelve years from now
What¡¯s going on? How did we get here?
Well to really understand population growth, we should really start at the beginning
Turns out it took all of human history about fifty thousand years
up to the year 1800 to reach the first billion inhabitants
but once we hit that mark, things started to move
The number doubled to 2 billion in just a hundred and thirty years
Two billion became three billion just thirty years later
It took fourteen years to go from three billion to four billion.
And we reached five billion thirteen years later
You can see what¡¯s happening.
Twelve years later, grand six billion and another twelve years after that
we¡¯ve reached seven billion.
What is surprising is that over the past fifty years
the actual growth rate has slowed,yet the size of the world¡¯s population continues to rise
So how can both things be happening?
To find the answer, we have to go back a few hundred years. Profound changes were happening
The Industrial Revolution transformed the way people live and work
With improved economic conditions, people live longer
Then in the twentieth century, better sanitation and modern medicine extended life even further
and family life began to change. Women¡¯ s roles were expanded
there were greater access to modern cultural reception and more kids were enrolled in school
All this led to smaller families and longer lives
This is what experts call ¡°a Demographic Transition¡±
that marks the shift in birth and death rates.
So what does it mean on a global scale?
To understand global, we actually have to think local
That¡¯s because demographic transitions happen country by country
and at any given time the world contains a mix of countries that are in various stages of transition
In the early phase of the demographic transition, both birth rates and death rates are high
These countries generally have very young populations and fewer older citizens
But as countries develop, living conditions improve and people live longer
Birth rates, however, are still high. So population growth is still rising
Now local countries that have transitioned even further
Life expectancy goes up while people have fewer children
But the population is still growing because of the greater number of people at younger ages
At the end of the transition, most population growth are stablelized with low birth and death rates
And in some cases, the population actually declines because there are more deaths and births
which gets us back to the original question:
why is world population still rising even though the actual growth rate has slowed?
The simple answer is because right now we are at the point of history
where there are still more people living in countries
with early transition with growing populations than people living in countries
with stable or declining populations. So there you have it
seven billion today and eight billion projected in another twelve years
Understanding how and why the world¡¯s population is growing will help nations
better plan for the future and for future generations