Tag: 7billion

Visualizing how a population grows to 7 billion (NPR)

The NPR has produced a nice visualization / video showing how population grew to 7 billion (original article):

If you want to model the improvement in child survival, you just turn the birth tap off (or nearly). Then, with wealth, prevention, healthcare and better food, the population will also grow older (death tap also turned off or nearly) and during a certain time, lots of adults will be economically active (i.e. they will work and consume). This is a demographic dividend. But it comes with a risk: at the next stage, there might be a disproportionately high number of people compared to / depending on a small number of active adults (the next generation). In addition, if you fill it up slowly but you also empty it slowly, the container risk to be full soon, it all depends on the various rates …

Note that this representation is also very effective to understand the basics of compartmental models in epidemiology 🙂

How to feed 7 billion people?

The world reached a population of 7 billion people at the end of October 2011. United Nations symbolically chose Danica May Camacho, a girl born in Philippine, to mark this global population milestone. I recently wrote about the world population getting older, about non communicable diseases becoming the most dangerous threat to health (here too) or about World Population Day(11th of July 2011). We are now 7 billion and new projections tells us we will be 9.3 billion in 2050. When I heard all the news around this, I couldn’t help but think about Hans Rosling’s presentation on population growth at TED Cannes, in 2010.

In this presentation, Hand Rosling made a small recap of the situation in 1960, when the world was divided between 1 billion wealthy people and 2 billion poor people. He made this situation more obvious by plotting the number of children per women -vs- the percentage of child survival.

Hans Rosling's population in 1960

Then, if you watch the movie (watch it at the end of this post), you’ll see how the different populations evolved to the situation of 2005 where the differences were still there but less marked than in 1960. And all this was thanks to soap, hygiene, education, vaccination, family planning, …

Hans Rosling's population in 2005

So, one thing is to worry about what would be the world with 7 or 9 billion people. Another thing is to prepare the environment (i.e. both our container – the earth, its ecosystems, its water resources, etc. – and its content – us, other animals and plants, etc.) to cope with such an amount of people. And a third thing is to try to curb that curve and find ways to slow the world population progression.

In the remaining of his talk, Hans Rosling states that one way to curb this population growth is to continue to improve child survival to 90%. This would help reach a sustainable size population of the world. Unfortunately there isn’t any “gold recipe” in order to improve child survival. Two general goals can achieve this (as well as achieve many other things): an improvement in education and a reduction in poverty.

Fertility predictors, from Science magazine

If you improve education (especially of girls/women because they will become/are mothers, they could give their voice in that matter if we give them enough power), you will decrease fertility. The less children you have, the more time you have to take care of each of them, to give them more education, to feed them properly. On the other hand, if you reduce poverty, you also decrease fertility and, at the same time, you have more wealth to take care of your children, to send them to school and to give them proper food. This is not always the case, just generally the case.

Improving child survival will not solve all the issues. An addition of 2 billion people during the next 35 years or so is something big and it will have an impact of every aspect of our lives. But I really like the idea of having a leveraging effect starting from the improvement of child survival.

I let you watch Hans Rosling’s talk, now …

Today is World Population Day


7 billion actions poster - UNFPA

They highlight 7 key issues to explore:




What will be your unique story?