More older Africans

When people read that the world population will rise from the current 7 billion to 10.1 billion by 2100, they tend to visualize a very crowded planet.  It would be more accurate to visualize a world pretty much like ours, except for Africa.  From The Economist:

THE world’s population will reach 7 billion by the end of October, according to the latest projections from the United Nations. For the first time the UN has attempted to look as far ahead as 2100, using various assumptions about how fertility and mortality rates might change over the years. The average of these estimates suggests that the global population will cross 10 billion by 2085. By 2100, 22.3% of people will be aged 65 or over, up from just 7.6% in 2010. The bulk of population growth is expected to come from the developing world. Africa’s population will rise from 1 billion in 2010 to 3.6 billion in 2100. In 1950, 32% of the world’s people lived in today’s rich countries. By 2100, only 13% will.

By 2100 we’ll have 3.1 billion more people, and 2.6 billion of them will live in Africa (the rest will be in South Asia.)  How many more schools will we need?  None, the number of kids and young adults won’t change.  (OK, to be precise we won’t need more schools than we need now, we will need more schools than we HAVE now.)  We’ll have more old people.  More people over 25.  BTW, the post’s title cheated a bit, as Africa will also have more young people, but this will be offset by fewer kids in places like East Asia.  Nigeria may have almost as many people as China.

What does all this mean?  I have no idea, just as people in 1911 had absolutely no idea what life would be like today.

I was 13 when The Population Bomb was published in 1968.  Thousands of years from now people may look back at 1968 as a very special time, when the world’s population growth rate peaked at 2.1%.  Or maybe not.



9 Responses to “More older Africans”

  1. Gravatar of Richard W Richard W
    9. July 2011 at 18:38

    Fertility is actually falling in most countries. When people fret about rising global population what they are really fretting about are improvements in infant mortality and people living longer. The global population figures sound huge but I remember a few years ago reading that all the world’s population could be housed with a back and front yard in an area the size of Texas. Providing water would be a bit of a problem.

    I have confidence that the world will figure out ways to feed growing populations. However, water could prove to be a real constraint on actually producing the food. Lots of areas have the water without the arable land and other areas have the arable land without the water. We already have the water desalination technology to overcome some of those problems. However, they require huge amounts of energy. Therefore, energy will continue to be the greatest challenge that the world faces.

  2. Gravatar of Demographics in 2100 | William D. Walker Demographics in 2100 | William D. Walker
    9. July 2011 at 19:10

    […] Sumner comments on U.N. population projections for 2100: What does all this mean?  I have no idea, just as people […]

  3. Gravatar of Indy Indy
    10. July 2011 at 05:18

    I can see a world of 10-Billion feeding itself – that’s only a 43% increase in global agricultural cheap-calorie production which North America could add on its own with just potatoes and canola oil grown on spare land.

    What those 10-billion won’t have access to is fossil fuel and especially petroleum. Today, the top 20 countries with only 840 Million people (so, 12% of the global population) consume fully half the world’s oil output. The last 2 Billion are using only 10% of the oil, and the last billion only 2%.

    We can add another 3 billion people if, like those last billion, they only need another 2% increase in oil each, but they’ll be at a very low level of per-capita consumption. Perhaps humanity will develop some alternative energy-production technology which, by then, will prove much cheaper than oil is today (who can predict such things 89 years out?) but I am not optimistic that we will get there in the next few decades.

  4. Gravatar of Scott Sumner Scott Sumner
    10. July 2011 at 06:04

    Richard and Indy, I agree with both of you. Energy is a bigger challenge than food, and even that will be solved one way or another.

  5. Gravatar of Rien Huizer Rien Huizer
    10. July 2011 at 06:53

    Population growth in Africa is basically irrelevant?

  6. Gravatar of ssumner ssumner
    10. July 2011 at 08:30

    Rien, I don’t think they’re saying it’s irrelevant, just that we will be able to feed 10 billion people. Or have I misunderstood your point?

  7. Gravatar of Indy Indy
    10. July 2011 at 14:29

    I’m not sure I understand what “solved one way or another” means because people use that expression to mean different things (though I won’t go all Rorty on you).

    Do you mean the tautological “Supply, whatever it is, and Demand, whatever it is, will intersect at some point and make a Price, whatever it is.” or do you mean you expect the emergence of cheap technological solutions, or something else?

    Obviously I’m in the “this is going to be a big problem for future development in my lifetime” camp. Here are my favorite data points. According to the IMF, from 1980-2010, World Real GDP grew from $24,800 to $63,000 current dollars (about 155%). World population only increased 56% – so on average people got much richer – good news.

    I think the food situation is utterly straightforward – the spare agricultural capacity is already there to produce the additional 2 Exacalories per year we would require with the technology we already have and cheaply. In the 30 years from 1978-2008, the FAO says that Wheat production went up 54%, Rice 79%, and Corn 110%. Not just providing for more people – but more calories per capita, and lots more meat.

    In the same time – global oil production has increased only about 30% (so, fallen per capita) and it’s fallen in absolute terms dramatically from peak in some of the most technologically advanced and richest countries in the world, precisely the ones I would have expected to develop those solution-technologies. (US: -33%, Norway: -37%, UK: -54%, Australia: -30%).

    The above data leads me to think the energy problem will be completely different from the food problem. The price elasticities of future supply are at least an order of magnitude away from each other.

  8. Gravatar of Scott Sumner Scott Sumner
    11. July 2011 at 18:20

    Indy, I meant will find more energy, or the price will go up and we’ll use less.

  9. Gravatar of TheMoneyIllusion » A green and pleasant land TheMoneyIllusion » A green and pleasant land
    28. July 2012 at 13:56

    […] Outside of Africa, the world’s population has nearly peaked (it’s 6 billion non-Africans, whereas in 100 years it’s expected to be 6.5 billion.)  Since most places are far less crowded than England, it looks like the world as a whole will never end up being particularly densely populated.  So why does it seem like it is?  Here are a few theories: […]

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