Will We Pass 10 Billion?

The fact that the mid-range projections for world population rose by nearly a billion people this week should have garnered a lot more attention than it did. The UN offers biennial updates of its world population estimates, and for the last few years, the mid-range (ie, the most likely scenario) has suggested that the world will peak around 9.2 billion people near the middle of this century, and then slowly begin to decline. The 2010 estimate, however, found that the decline is no longer considered likely, and that by 2100, the world may have as many as 10.1 billion people.

This raises a whole host of issues, which I'm going to consider over the next month. Raj Patel has already usefully offered one answer (which I don't wholly agree with, but it is interesting) to the question of whether we could feed 10 billion people. But first I want to ask whether the population estimates themselves are realistic.

Now it is important to remember that these aren't flat numbers and this isn't a census. It is an estimate, with a range of possible outcomes based on a whole host of variables, including behaviors, death rates, education, etc.... Moreover, the longer range (2050-2100) numbers are more speculative, because the people who will be giving birth then have not yet been born. On the other hand, many of the people who will be having children between now and 2050 already are born - so we have a sense of those people. It is certainly possible they could choose to have more or fewer children than demographers estimate, but the basic number of potential parents is close to being fixed.

Much of the change predicted is projected to occur in Africa, where the demographic transition has been taking place, but more slowly than in parts of Asia and South America. The other major factor that is expected to shift African demographics is a continued expansion of access to HIV drugs, thus shifting lifespans from in the 40s and 50s back towards the 70s. Globally, the report finds:

Life expectancy is projected to increase in the three groups of countries considered.
In 2005-2010, average life expectancy at birth was lowest among the high-fertility
countries, at 56 years, mainly because many of them have generalized HIV/AIDS
epidemics. Nevertheless, given the advances made in reducing the spread of the disease and the expansion of antiretroviral treatment, the projections assume a continued decline in mortality rates from HIV/AIDS as well as from other major causes of death. Therefore, the expectation of life among high-fertility countries rises to 69 years in 2045-2050 and to 77 in 2095-2100.

Among intermediate-fertility countries, average life expectancy was 68 years in 2005-
2010 and is projected to rise to 77 years in 2045-2050 and 82 in 2095-2010. Lowfertility countries tend to have, as a group, higher average life expectancy. It was
estimated at 74 years in 2005-2010 and is projected to rise to 80 years in 2045-2050 and to 86 years in 2095-2100. Globally, life expectancy is projected to increase from 68 years in 2005-2010 to 81 in 2095-2100.

One of the things to know about this report is that while it does in a limited way take climate change into account, it does not take resource limits into consideration in a serious way, and it generally presumes levels of economic growth and globalization will continue. As much as I would love to see anti-retroviral drug access expand in Africa, and continued lifespan increases across the globe, I'm not at all sure that I think these presumptions, particularly the assumption of continued economic expansion and access to the trappings of middle class life for more people are realistic. To the extent that population growth has depended on fossil fuel growth and the economic expansion it fuels, we must ask what the future of population is in a world of material limits.

We should note, for example, that while lifespans have continued to increase in the Global North, poor areas of the US have for the very first time in recent years show signficant declines in overall lifespan in its poorest areas. Other poor areas have seen no increase in lifespans. It would suggest that if there is an era of economic stagnation or decline, projections for the Global North or parts of it may be inaccurate. Indeed, we have seen the ways that collapse affects lifespans after the Soviet collapse, where lifespans for men dropped back into the 50s.

Access to anti-retrovirals, so desperately needed in much of Africa, has expanded dramatically. It is hard to write this, because this has been such a necessary gift to societies being destroyed from the inside out - suggesting it might not last is actively painful to me. And yet, access to HIV drugs depends heavily on industrial supply chains, on a nascent pharmaceutical industry in Africa that relies heavily on imported raw materials, and on the importation of generic drugs in quantity over long distances. More fundamentally, they rely heavily on international aid.

I am not expert enough in the issues of drug manufacture and distribution to argue that the drugs will not be available in an era of economic decline - indeed, I can't but hope they are - but it is certainly a vulnerable spot, because it depends heavily on both the affluence of the Global North, which has a long history of abandoning its aid commitments when life gets inconvenient or economic crisis hits (consider the abandonment of the commitment to alleviate the emergent food crisis of 2007-8) and also on manufacture, shipping and transportation that are heavily energ intensive. If I were queen of the world, manufacturing HIV drugs in Africa would be one of those best use things that one reserves oil and other resources for. Historically speaking, Africa's needs have often come last, and when oil prices spiked in 2007, many African nations saw disruptions of needed supplies.

If lifespans are in question in some measure, are birth rates? Again, there are many variables here, but what we can say is that periods of cultural and economic crisis do tend, at least in the Global North and often in the South as well, to send birthrates rapidly downwards. Consider the drop in TFR in the US during the Great Depression, which was dramatic - couples couldn't afford to marry, married couples delayed childbearing. Moreover, the most economically productive people in any economy tend to be those of childbearing age - massive economic stress on them tends to result in reduced childbearing at least in nations where children represent an economic burden.

The situation is more complicated in poor nations with high fertility, where often children are one of the few economically valuable assets a family has. In Nigeria, for example, a child begins to produce more than he consumes by eating by the time he is six years old, and by 12, may produce as much economically as an adult. Add to this the high death rates and lack of security for the elderly and for women and you see that economic value of children in difficult times is somewhat different - for example Vandana Shiva and Maria Mies point out in _Ecofeminism_ that an Indian Woman in the rural areas has to have five children in order to be sure that when she is 60, she will have a living child able to support her. But even in the world's poorest places, the demographic transition is ongoing and crises tend to have a negative effect on overall childbearing.

The one thing we can be nearly certain of is that this will be a century of crises - and while the exact nature of the economic, climate and energy crises we face is up in the air, and I do not make any claims about what effect they will have on human fertility, it is worth asking at least why the UN analysis presumes the rates of growth it does, and whether this analysis would more wisely include the problems of resource limitation.

Resource limits are a lousy way to solve the population problem, obviously, and no one advocates for them. But we need good data on population, and the problem with the UN projections is that they leave out large parts of the puzzle. It is certainly possible that we will reach 10 billion people - but we are not making our assumptions based on the real underlying ecological, energy and economic limits we are facing, so we simply don't know.


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Is there any other way population problems get solved other than resource limitation -- either from the natural world or from being deliberately withheld by those in power? Individuals may be smart, but as a race we haven't gotten that smart yet.

I don't hold much hope for aid for Africa or any other country. Although it's a pittance, there is strong public support in the US for reducing or eliminating foreign aid, and the other countries in the Global North are likely to follow our lead, at least for a while yet longer. As our own financial woes unfold -- some real, some hyped -- foreign aid will be on the chopping block despite that fact that in the long run it saves us money. (And is the right thing to do.)

My sense is that we will continue to see new and dangerous diseases arise, and eventually one will be both highly contagious and highly lethal. If it arises in the 3rd world, the chance of early detection and containment is bleak, and our own greed may be our downfall.

One of the things I've tried to bring up over on The Automatic Earth is the glaring omission, both in economic projections; and here in the UN population projections- of ANY inclusion in the calculations of "disasters".

Somehow, on university campuses, they think earthquakes, tornadoes, vast forest fires, floods, exceptional droughts, tsunamis, volcanic eruptions, and nuclear powerplant meltdowns - never happen.

Actually, with the exception (I think) of major volcanic eruptions; 100% of those items are going on currently, or have gone on somewhere in the world since Jan. 1 of this year.

The level 9 earthquake/tsunami/meltdown in Japan has without question altered the Japanese economic situation for years ahead; and I would bet it will have population repercussions, also; though I would hesitate to say what.

Looking ahead, in the next century- there will be more region-wide earthquake disasters. Droughts; floods. Maybe Yellowstone will blow? Maybe the Big One will finally hit California? Maybe France will have a Fukushima style meltdown (they have 70+ reactors; each waiting for some human to be... human).

The forecasters respond "oh, you can't put that stuff in, it's unpredictable!" and my response is no, it's inevitable; just uncommon and erratic.

Tornadoes are way up, statistically. I'd know, Minnesota was #1 in the US last year- for the first time ever. Record flooding on the Mississippi today; thousands of acres of crop land removed from production for this year, anyway.

None of this makes foresight any easier. But; we need to get in the habit of thinking about it, anyway. And maybe avoid making plans and investments that take no account of inevitable natural upheaval.

Oh, and I left out asteroid strikes, just for fun. :-)

I think Nicole's last paragraph is a reasonable projection. We are having more and more contact with animals,'bush meat', and will probably pick up new animal transfer diseases. Bush meat gets shipped to ethnic groups in the USA, and probably other areas of the world. We are also converting large areas to farmland and likely exposing ourselves to new soil bacteria. I think Legionnaires' disease is of soil bacterial origin. My personal guess is that we will never make eight billion because of world wide epidemic(s).

By Jim Thomerson (not verified) on 06 May 2011 #permalink

I didn't mean to leave plague out of my list; it's definitely way up there probability-wise; but Nicole had already pointed that out. Part of the "big picture" relating to plague is the increasing prominence of antibiotic resistant "tool-kits" which the microbes are passing around, with increasing rapidity. Yep, it's a side benefit of CAFOs, really.

We actually had a real-world experience there ourselves, since Jan. 1. Spice (my spouse) somehow picked up a CA-MRSA infection. And us living out in the woods. Likely she got it at school, where she volunteers 1 day a week (teaching history, since the Art teacher now teaches history, except she has no history training...).

Totally occupied our lives for a month; finally did manage to "get" the infection using 3 antibiotics simultaneously (all 3 of which I happen to be allergic to).

While tragic for some, tornados, earthquakes and the like don't put a significant dent in the global population to be statistically relevant. The largest tornado outbreak in recorded US history occurred last week, and it only killed somewhere between 300-350 people, some of those past their breeding age or already have children. Losing a few tens of thousands tomorrow would probably not statistically move those numbers.

A natural disaster would have to be MUCH bigger to really affect a population projection dealing with billions. Say, one of the mega-volcanos. Or a large asteroid strike.

I'm inclined to believe the only *probable* large event to move that number is either plague(s) or flat out starvation. If I'd had to pick one, I'd wish for a massive plague of infertility. Just not "The Handmaid's Tale" version of that.

"While tragic for some, tornados, earthquakes and the like don't put a significant dent in the global population to be statistically relevant"

well. Let's count a little.

Haitian earthquake; "Haitian government reported that an estimated 316,000 people had died, 300,000 had been injured and 1,000,000 made homeless"

Indian Ocean tsunami: "over 230,000 people in fourteen countries, and inundating coastal communities with waves up to 30 meters (100 feet) high."

Wikipedia, in both cases. We can argue about what is statistically "significant" - but as a biologist, I assure you that removing a quarter of a million individuals from a population will have a real effect on the growth of that population, for decades to come.

Even the paltry tornadoes (which are increasing) - the real point is not the direct mortality; it's the disruption of the ecosystem; which goes on, and on; with increasing effects on reproduction. It will be a couple years before we see the effects on Japanese population growth; but the probability that the psychological, and economic effects of Fukushima - and the tsunami- will actually effect the birth, and death rates in Japan.

For many of the communities around the Indian Ocean, their ability to provide medical services; educational opportunities- have been drastically set back. Etc, etc. Birth rate and infant mortality will change.

That's the point; not the immediate mortality; though I do feel 300,000 Haitians are "significant." Infant mortality among the 1,000,000 homeless- most of whom are still homeless- is pretty much guaranteed to go up. Cholera- is now endemic in Haiti; and is not going away.

Wikipedia: "As of July 2010, as much as 98% of the rubble from the quake remained uncleared. An estimated 26 million cubic yards (20 million cubic meters) remained making most of the capital impassable,[233] and thousands of bodies remained in the rubble. The number of people in relief camps of tents and tarps since the quake was 1.6 million, and almost no transitional housing had been built.

"According to a UNICEF report, "Still today more than one million people remain displaced, living in crowded camps where livelihoods, shelter and services are still hardly sufficient for children to stay healthy".[250] The Interim Haiti Recovery Commission was set up in April 2010 and led by former US President Bill Clinton and Haitian Prime Minister Jean-Max Bellerive to facilitate the flow of funds toward reconstruction projects and to help Haitian ministries with implementation. As of January 2011, no major reconstruction has started.[247] Amnesty International reported that armed men prey with impunity on girls and women in displacement camps, worsening the trauma of having lost homes, livelihoods and loved ones.[251]"

Likewise; in the Indian Ocean: "the Asian Development Bank reported that over US$4 billion in aid promised by governments was behind schedule. Sri Lanka reported that it had received no foreign government aid, while foreign individuals had been generous."

Systemically; the world is failing to respond to these disasters. Initial pledges of monetary aid are regularly failing to be fulfilled; stories from the front lines indicate much of the aid money winds up stolen.

As we go forward- this aspect of it all, can only get worse.

Greenpa: "We can argue about what is statistically "significant" - but as a biologist, I assure you that removing a quarter of a million individuals from a population will have a real effect on the growth of that population, for decades to come."

A quarter of a million people is ~0.000036% of the GLOBAL population. Sure it's a lot of people but it's insignificant in the big picture.

Besides, your whole premise that natural disasters are not counted is incorrect, the death rate includes deaths from all causes. You can make wild guesses about future plaugues, asteroids and super-volcanoes, but the only valid assumption you can make about natural disasters is that they will continue to kill people at a fairly steady rate.

Do I think we will reach 10B? - Not a chance in hell, but it will be an ecological disaster of our own making that prevents it.

We are also converting large areas to farmland and likely exposing ourselves to new soil bacteria.

Would surprise me. There's almost no arable land left that isn't already under the plow.

What's likely to become a problem is Peak Oil. Modern agriculture is "oil into potatoes".

By David MarjanoviÄ (not verified) on 06 May 2011 #permalink

It is certainly possible that we will reach 10 billion people - but we are not making our assumptions based on the real underlying ecological, energy and economic limits we are facing

Well of course not. To do otherwise would leave the UN open to accusations of political bias from the cornucopians.

By Chris O'Neill (not verified) on 07 May 2011 #permalink

Of course "we" could feed 10 billion people. As Greenpa already pointed out in the past, all that food is *already* being produced.

That is not the question folks should be asking. First of all, are "we" prepared to alter the economic system so that the food produced gets to the people who go hungry? And if "we" are, how do we go about it? And second, that if we don't want there to be 10 billion people, then maybe we should stop overproducing food?

Well, I'm an unabashed cornucopian, but...

Our real sustainability problems relate to the fossil-fuel economy: and not just because fossil fuels are nonrenewable, or even because of the environmental effects of its pollution (both direct and through climate change); but also because the investment in a fossil-fuel infrastructure is causing us to "plateau" - not to take advantage of technologies that could jump us on a tremendous level. (A troubling analogy: ancient Romans knew of the steam engine and windmill, in primitive forms, but never developed them -- sometimes thought to be due to a slave-driven economy).

I don't think there's a "carrying capacity" problem as such. People at the beginning of the Industrial Revolution would be astonished that the current population could exist; Neolithic farmers wouldn't believe the Roman Empire's population was supportable; hunter-gatherers would have been astonished by the population agriculture could support. Technology and infrastructure is crucial; and even environmental damage has more to do with economic choices (and our currently very inefficient system) than population as such.

Presumably there's an upper limit *to Earth* (though I think it's far higher than anyone but the wilder SF authors expects -- even leaving large tracts of wilderness; I tend to think the next big transition will mean much more compact cities and super-intensive agriculture), but I don't think we will hit it for several centuries at the very least, by which point we will not be limited to Earth anymore, at which point the sky's the limit.

By intercostal (not verified) on 07 May 2011 #permalink

Present rate of world population growth is around 1%. Present world population is around 7,000,000,000. The growth is in spite of wars, famine, earthquakes, tsunamis, etc. That is about 70,000,000 new mouths each year. The reason people starve is that they don't buy enough food to eat. This comment focuses on the economic aspect. As long as there are many poor, there will be many malnourished or starved.

By Jim Thomerson (not verified) on 07 May 2011 #permalink

Alan: "A quarter of a million people is ~0.000036% of the GLOBAL population"

well, somebody needs to check our math. I get a different number: assuming 7,000,000,000 and 250,000 = .000036; or .0036%.

Which, I have to admit, is a much smaller proportion than I was getting my mind around. So, I'm human. A billion is incomprehensible. But a quarter million; I can see.

David: "There's almost no arable land left that isn't already under the plow."

When the Lester Brown people put that bit out a few years ago; that's when I quit ever paying any attention to anything they say. I'd just come from a month in central China. As packed and intensive as it gets. And I guarantee, both their ag scientists (who I was working with) and myself could EASILY see land available to double what was currently being worked; not including remote areas- with stone rice terraces that had been abandoned hundreds of years ago, in a previous population collapse.

I've kept my eyes open ever since- and confirmed it over and over. There's a huge amount of land that could still be "plowed" and "brought into production". It would be an even bigger disaster than what's already underway- but that wouldn't stop people from growing food on it, until something else stops them.

Heh. Lester Brown's just a publishing machine now. Nothing to see there, folks, move along. :-)

Greenpa; Yeah, you're right I forgot to divide by 100 to convert to a percentage.

Oh and speaking of China, they turned an area the size of France from goat herding scrub land to orchards for $500M over 20yrs. They also more than doubled the standard of living for the locals in the process. Google "loess plateau", 20yrs ago it was considered the most eroded place on earth (think Afgan hills), but is now one of the top apple producing regions on earth (think misty tree covered hills).

Sharon, I think the cornucopians have taken over your blog.

By Chris O'Neill (not verified) on 07 May 2011 #permalink

Well ... as an unabashed cornucopian... I hope I'm not "taking over" anything.

But just using the term 'cornucopian' isn't an argument. There has never been a Malthusian collapse in any society but utterly stagnant ones (eg Mayans, Easter Island) I simply have not seen convincing evidence that there are fundamental (as opposed to given-our-current-fossil-fuel-economy) limits anywhere *near* 10 billion.

The real risk would not be population but a stagnation of science due to the destruction of the cultural/philosophical framework it needs. (Ironically, a lack of population growth could make it worse - it's generally related to cultural stagnation e.g. late Rome, late Sparta).

By intercostal (not verified) on 08 May 2011 #permalink


I won't argue that 300,000 Haitians is significant. It is, and it's tragic and maybe you cna imagine that many people but I really can't except as an abstract concept. But -- it is probably not statistically significant. As Alan pointed out, these are normally occuring deaths and are counted in population projections. We'd need to see a catastrophic and unprecendented population drop to shift that 10 billion projection.

I'm between the doomers and the corncopians. I don't believe in zombies nor everyone getting their own happy 4 season intensively farmed homestead.

But I totally agree with you that if we use modern farming methods to plow under all the land we be merely hastening our ecosystem collapse. "Goat herding scrub land" has biological value, and turning it into lush apple orchards isn't necessarily a positive thing for the planet. Especially not the way the Chinese grow apples for US export.

Gawd, what a silly thing for the US to import... but that's another rant altogether.

I should be clear - I don't believe that either the low end projects for planetary carrying capacity nor the high end projections are correct. I know, for example that Catton and others have projected 1 billion or so - but the UN noted in 1999 that there were 2 billion people on the earth presently living almost entirely on low-or-no input agriculture, mostly on marginal lands. That is, there are already twice that number of people surviving without much in the way of fossil inputs.

In _A Nation of Farmers_ Aaron Newton and I run the numbers on this, and we conclude that we technically could feed the previous mid-range projections, 9.2 billion, but not indefinitely, not at a low ecological cost (although we already produce enough food to feed 9.2 billion, were it equitably distributed, so the ecological damage isn't more than at present and could be considerably less if you substituted low input agriculture for high), but more importantly, we won't - we have no system for the truly equitable distribution of food. The issue, I suspect, apart from whether we will hit 10 billion is that we won't do what is necessary to keep that from being a nightmare, anymore than we are now.

Intercostal, in many ways I'd argue we are stagnant society - but also don't think the historical precedents are that relevant, because we've never been this close to world carrying capacity. Ultimately, we are, at this point, talking about millions of local carrying capacities which vary, but we are also in the process of depleting seas and warming the planet in ways that radically reduce the capacity of the earth to support a reasonable population. Calling something cornucopian isn't merely an argument, but you'd have to make the case based not merely on precedent but on the actual biological degradation of our natural resource base. The idea that science is apart from the resources that support it seems to me to be an argument that would require considerable support - for all that it is a common presumption, it doesn't stand up very well.


In case anyone is still following this thread; this is an example of what I was trying to point out:


Record flood. "Vast" economic impact. Which will affect reproduction (and I couldn't tell you if it would be up or down) far beyond the region of the flood, and for years to come.

Global warming is going to increase the number of natural disasters- far beyond historical proportions; making predictions based on historical frequencies inaccurate- in my opinion potentially VERY inaccurate.