Is the population Growth out of Control ??

 

The respected broadcaster and naturalist, Sir David Attenborough, said recently that population growth was "out of control" - but the UN 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. Since I first started making programs 60 years ago, the human population has tripled," said Sir David.
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.

David Attenborough

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.

Also, in developing countries the UN predicts rapidly expanding populations. In Nigeria, for example, it expects the current figure of roughly 160 million to increase to almost one billion by the end of the century.

Taking its population as a whole, this century Africa's story will be one of incredible growth - beyond that of any other region in the world. It's expected to account for more than half of the total global population growth between now and 2050.

The world's population hit seven billion in 2011. After growing very slowly for most of human history, the number of people on Earth has more than doubled in the last 50 years. The UN predictions also assume that all fertility rates will eventually converge towards replacement rate; that is, the birth and death rate will be about equal. What's more, small changes in fertility rates have a more pronounced effect over time.

 So is the population growth out of control? Taking into account the growing scarcity of food and fresh water, perhaps we should aim for that replacement rate as soon as possible.