The respected broadcaster and naturalist, Sir David Attenborough, told the BBC recently that population growth was “out of control” - but one expert says the number of people on the planet could peak in 40 years. Who should we believe?
"The world’s population is increasing out of control," Sir David told the BBC’s Today programme.
"Since I first started making programmes 60 years ago, the human population has tripled."
Two striking claims.
Let’s take the second one first - that the world’s population has tripled in 60 years.
In 1950, around the time Sir David began his broadcasting career, there were 2.53 billion people in the world. Sixty-three years later and the latest estimate of world population is 7.16 billion.
That is a little shy of tripling - more like a factor of 2.8 - but it’s not far off.
The “out of control” claim is less easily measurable, but perhaps it could be interpreted as the idea that the population will continue to grow at the same rate, roughly tripling in 60 years.
If this happened, the world population would reach almost 40 billion people by the end of this century.
But the latest United Nations projection puts the figure at little more than a quarter of that - less than 11 billion.
That’s still 50% more than we have today, but it shows the UN expects much slower population growth in the decades to come than in decades gone by.
Some might consider that an increase in the world population from seven billion to 11 billion by 2100 still represents out-of-control population growth.
But this UN figure - contained in its World Population Prospects, published every two years - is considered by one expert, at least, to be much too high.