The UN, IMF, and most national agencies also release their numbers.
In general, world GDP growth — and its correlates, like HDI — is stable enough to predict population growth. As a country gets richer, fertility falls: women get careers, jobs require more education for children, people start to rely on savings, instead of family. The aggregate numbers are smooth and predictable. At least, for a reasonable time horizon.
But you need to fine-tune the model at the right aggregation level. For example, the US, EU, Japan have similar GDP levels, but fertility in the US remains high. Census data helps settle down these issues.
Ok, so for everyone that can barely use that terrible website, the number that they have in 2050 is 9.71 billion. Someone else can try to figure out how to download that data and then give an actual estimate as to when the population will flat-line. Maybe find a way to get it into excel and then apply a log fit to it, or soemthing. Hell, I ain't gonna mess with that terrible site again.
Edit: Forgot to thank my parent comment for finding the data in the first place!
It seems their data is based on UN research, who publishes regular population projections. The latest revision, published in 2015, apparently only goes up to 2100, at which point they still predict growth. However, if you look at projected growth as it's presented in this article:
You can see that the growth is rushing towards zero and almost crosses it in 2100, giving a maximum sometime around 2115. But I wouldn't really count on any projection's accuracy that far into the future: what really sticks out is how the historical growth is extremely jagged, driven by crises and revolutions, then becomes ridiculously smooth as soon as it turns into a projection. It just screams out "this is a very rough approximation and probably wrong".
Ok, I get what the article you linked to is saying, but I think it's really uninformative. Those graphs are the derivative of the population. What I would most like to see is the absolute number of people on earth over time and then into the future. The derivative, though important, is not as useful (to me) as the absolute number. Hans Rosling has some good TED talks on it, but I think they are probably out of date by now.
> You can see that the growth is rushing towards zero and almost crosses it in 2100, giving a maximum sometime around 2115.
You're not reading that data correctly, or perhaps, you're simply not accounting for the death rate. The death rate will surpass the growth rate in those projections somewhere between 2050-2080, which means population peak will be in that time frame, not a century from now.
Hmm, I think you're the one that's not reading it correctly. The growth rate takes into account both death and birth rates. As Balgair points out, it's simply the derivative of the total population. And the UN's projections do not show population peaking between 2050-2080.
He also just assumes some naive correlations based on some graphs, without doing any rudimentary statistics (e.g. chi squared to check if the correlations are even notable), and then plugs the numbers in and see's what he comes out with.
Instead, he should base his model on data from say 2000, and then predict the population in 2015, and then if that's correct, he might be able to say something about 2065 with any degree of certainty.
That he disagrees with other predictions suggests his model is wrong, but it's difficult to say how.
The description of this suggests the analysis is a lot less plausible than the actual figure:
- Birthrates are assumed to fall linearly all the way to zero, despite an abundance of reasons why that's obviously not likely to be the case
- If I'm reading it correctly, countries' birth rate declines are estimated as a discrete property of arbitrary HDI labels rather than a function of actual HDI score. Which in practice means that minor threshold differences decide whether birthrates in a country to fall sharply across one decade and less sharply in another
- Small islands are given equal weight to China and India in gauging an HDI-bracket's average birth rate
- The HDI brackets aren't even copied correctly, and thus many ultra wealthy territories like Bermuda and Gibraltar are placed in the "low HDI" bracket. That probably means the model massively underestimates the YoY decline in birthrates in low development countries (which I suppose at least works in the opposite direction to incorrect assumptions made about birthrates dropping to zero)
- There's really no justification at all for projecting a death rate that varies between ~1 and ~15 per 1000 as a uniform 8 per 1000, especially not when data on population age distributions and life expectancies exists. (The only saving grace is that it isn't that far from the figure for India and China which have a disproportionate effect on the model)
"The table above already shows that birth rates go to zero by 2065."
Uh.... This seems incorrect. Sure we can extrapolate the declining birthrate all the way down to zero, but realistically it will level out somewhere since humans will never stop producing more humans. Granted it might be a lower birthrate, but never 0.
He is not, and that is the primary flaw in this analysis.
Estimates that the recent declines in birth rate will continue until 0 annual births, once the birth rate stops the death rate continues at pace, and kills everyone eventually.
Flawed in many ways, but that is the biggest mistake. A good example would be the temperature has dropped 20 degrees in the last month at this rate we will reach absolute 0 in around 2 years.
We're already seeing governments like Russia imploring people to reproduce and giving incentives to do so. Also low birth rates in developed countries are in-part affected by the need for both parents to build careers, if the world economy collapses because of declining population (which results in a lack of growth and also soaring healthcare expenses) then we'll probably see reproduction increase again - especially if coupled with the above mentioned incentives.
Birth rate will never decline to zero, as the next generation will be biased more to whatever it was what made their parents to get kids, and less to what made people childless.
For example in the extreme case that Facebook would make people sterile, than some day simply the Amish will rule the US.
The author's models for population growth are too rudimentary to be accurate over more than one or two decades. I find it really hard to believe that the growth rate for countries will maintain a constant value for the next few centuries.
There are near infinite factors influencing birth rate that are all interconnected. No model can accurately account for all of this, but the models linked don't even attempt to cut very deeply.
That's a huge "what if", on top of what's already an impossible-to-predict situation. But if we're going to entertain this, we should also factor in the other circumstances that are likely to come with this scenario:
I spent a chunk of my life adjacent to bio/med research and my conclusion is radical life extension by purely biological means will probably remain unfeasible. Genetically, we're millions of years worth of horribly interdependent spaghetti code, there is no fixing this mess. So - barring the option to upload yourself to silicon - death won't be obsolete by 2065.
However we might see some very, very moderate increases in life expectancy across the board, even in comparatively poor nations, as long as they're not living in abject poverty. This would be cause for concern, but data from industrialized nations suggest a major regression in births once a population becomes (somewhat) wealthy and healthy.
The desire to procreate boundlessly may very well be a deep-seated instinct triggered by living in precarious environments. If dying slows down, it's because of improved living standards and medical care, the same things that stop over-procreation.
It seems to me that in order to control Earth's population, we need to address poverty, which incidentally would solve a huge slew of other humanitarian and ecological problems.
First, I don't think you are adequately compensating for the availability of new technologies, such as medical molecular nanotechnology, which we will certainly have by 2065. The entire approach to medicine that we use now is likely to be obsoleted in that time frame, leading to the eradication of most terminal diseases.
Second, one doesn't have to eliminate biological death entirely to muck up those forecasts. We know from super-centenarians that those who are lucky enough to not suffer any life threatening conditions nevertheless kick the bucket around age 120. Even if that's not fixed by 2065, it's almost double the average life expectancy and that is not factored at all into the OP's calculations.
Third, birthrates are currently constrained by menopause in women. Most women don't have more than a few children in the developed world because they are biologically incapable of having more. And although men have the capability to have "2nd families" (with another woman later in life after their previous children are grown), women do not. Defeating/controlling menopause is therefore more likely to result in either larger families, women choosing to have a second family at a later stage in life, or women who would have otherwise missed their chance having a family at all. Again, fertility advances are not factored into the OP's calculations.
Thus although I could argue that biological immortality is not "unfeasible", I don't need to. The OP has failed to factor in reasons why the death rate will go down and the birth rate will go up, making his charts too conservative.
To me, it also means that the "upload to silicon" stage is unlikely, because it probably requires understanding and reimplementing (possibly bug-for-bug, in some places) the original, for, uh, carbon compatibility. (And if we really understood it that well, we'd probably just fix the original...)
Medical care is unaffordable / unsustainable in the high HDI countries and doesn't exist in the low HDI countries.
Would have been interesting to look at the impact on the high HDI countries of mass invasion and demographic replacement. Many of those countries won't be in the "very high" category much longer. That will have the obvious impact on birth rates etc. Ditto long term trends in income inequality, in that population stats meant something when populations were more equal, but the average of oil and water isn't a salad dressing.
> Medical care is unaffordable / unsustainable in the high HDI countries
Maybe. Or maybe we're so wealthy and have so few kids that the health care industry is draining off the excess?
In either case, I think it's hard to make such generalizations about a group that includes both the US and countries that have single payer health care.
"A common objection against starting a large-scale biomedical war on aging is the fear of catastrophic population consequences (overpopulation). This fear is only exacerbated by the fact that no detailed demographic projections for radical life extension scenario have been conducted so far. This study explores different demographic scenarios and population projections, in order to clarify what could be the demographic consequences of a successful biomedical war on aging. A general conclusion of this study is that population changes are surprisingly slow in their response to a dramatic life extension. For example, we applied the cohort-component method of population projections to 2005 Swedish population for several scenarios of life extension and a fertility schedule observed in 2005. Even for very long 100-year projection horizon, with the most radical life extension scenario (assuming no aging at all after age 60), the total population increases by 22% only (from 9.1 to 11.0 million). Moreover, if some members of society reject to use new anti-aging technologies for some religious or any other reasons (inconvenience, non-compliance, fear of side effects, costs, etc.), then the total population size may even decrease over time. Thus, even in the case of the most radical life extension scenario, population growth could be relatively slow and may not necessarily lead to overpopulation. Therefore, the real concerns should be placed not on the threat of catastrophic population consequences (overpopulation), but rather on such potential obstacles to a success of biomedical war on aging, as scientific, organizational, and financial limitations."
That study is flawed. It's "optimistic" scenario still assumes menopause and therefore a fixed number of children per woman in the population. Yet a level of medical technology that can eliminate aging entirely would also be able to reset the biological clock (or create artificial wombs, etc.).
Or at least, many fewer people. If we get to a point where we're extending the average lifespan by a year every 7 or 8 years, up to an average ceiling of around 100, that has big implications. Demographic trends can probably predict birth rates decently, but probably not the overall population 50 years into the future.
Why do almost no population projections take climate change into account? We're rapidly heading towards a much less habitable earth. The projections I've seen with Africa at a population of 3-4 billion people by 2100 would be laughable if the whole situation wasn't so damn tragic.
Because current projections don't reach population levels where we exhaust the capacity of the earth, at best we'd face reduced material wealth.
Why the situation tragic? The universe does not care the sea levels or temperatures are different from what they were in 1700, just as the universe does not lament the great oxidation event which wiped out most of the species inhabiting the planet at the time.
In fact I'd argue that most humans are elated that cyanobacteria 'destroyed' the planet.
What do you mean by "capacity of the earth"? People per square metter of land? Consumption of oxigen? Consumption of fresh water? Per capita arable land and average agricultural output?
You could argue that we are already past the carring capacity of Earth as of today, and the reason we do not see a massive dieoff today is that we are, so to speak, burning our runaway instead of generating (enough) revenue.
With regards with your "Why the situation tragic?" comment... I also felt a great relief when I realized that we (as global society) will not wipe life on earth, and probably will not even wipe human life on earth with our colective stupidity.
However, a drastic reduction in population is due during the next 100 years or so, and most of it wont be voluntary. A lot of needless suffering is going to happen, and no, it will not matter much in the grand scheme of things. Do you really need to be so smug about it, though?
"Tragic" relates to humans, not the universe. Yes, humans are elated that cyanobacteria changed the face of the Earth, and would be quite sad if a similar event happened now that wiped out humanity.
This nonsense about "the universe doesn't care about our climate" has got to stop. No, it doesn't, but humans also don't care about what the universe cares about.
If you want to take such a large view that the fate of people doesn't matter, then go for it, but don't be puzzled when you end up in a tiny minority by doing so.
Just about every model shows significant increases in drought and desertification across most of the world's currently arable land with more than a couple of degrees of warming, which is the path we're currently on. Couple that with the fact that most land at far northern latitudes does not have the soil quality necessary to support large-scale agriculture, and we're looking at global famines that billions of people are unlikely to survive.
we're looking at global famines that billions of people are unlikely to survive
If I were part of a shadowy oligarchic cabal running the world, I'd be willing to trade-in worldwide chaos for the 21st century equivalent of a Hydraulic empire, where technologically enabled food production replaces irrigation.
>Conspiracy trash aside, if there are billions to be made helping the world avoid yet another Malthusian disaster, someone will make it.
Who made their millions off the Irish potato famine, other than the British businesspeople who caused the famine by making Irish food unaffordable to the Irish?
That's a huge simplification of the famine. The root causes of the famine are generally attributable to rental law in Ireland and the disincentives it created towards farmers investing in land and/or farms scaled to the right size for economies of scale.
Well there, you said it yourself. There were tariffs causing a market distortion at play. People were already making money off of that, and acted to protect it. That's not the only Malthusian disaster the world has faced.
1. NOT the whole world is heating up. It varies and some places are cooling, but no, generalise.
2. Areas like Russia and upper Asia will provide more arable land, these countries will experience a boon
3. The problem isn't the world, the problem is the sky high population growth in Africa/Middle East. Google "Population of ANY AFRICAN/MIDDLE EASTERN COUNTRY"
I think everyone wishes you could be correct but the situation where tundra/permafrost areas warm to a point that it is possible farm would cause a catastrophic release of Carbon on par with direct human activity.
But the problem is, as you go further from the equator, you get less square miles per degree of latitude. So if we lose arable land around the equator, and gain it in Siberia, that's still a net loss of arable land.
Limits to Growth, whether you agree with their conclusions or not, is an actual model.
The google docs above is one guy fiting a curve to a bunch of demographic statistics. There is no real causality there, no attempt to make an interpretation of the numbers. If he would have done so, he would - as others have already pointed out - reached the conclusion that: "Since birth rates decrease when people's lives improve, Progress will make our life so fulfilling that we will stop having children altogether. Then we will live happily ever after until we all die of old age."
Is this such a bad thing. Third world countries are becoming westernized giving us a continued growth of our markets even though the population might shrink.
Automation might make manual labor a thing of the past. We might not have enough jobs or natural resources to support a growing population.
Sadly I feel like studies like this don't take into consideration what a ww3 might do on the world's population long term. We are in an unprecedented time of peace which might not last to 2065.
Also revolution. Automation vs labor vs 1848 and all that. Where there is food vs where there are hungry mouths are not obligated to match up as they do now.
It would be interesting to analyze food production capability at various levels of petroleum production and then analyze the probability of those various levels of petroleum production. The days of powering your oxen with some acres of hay are long gone, takes quite a few calories of fossil fuels to generate each calorie of food.
Fossil water is another interesting concept. The east of the USA has more water than we know what to do with, we'll be OK, but the west currently lives off rapidly emptying aquifers, and once those are pumped dry, the population will revert to 1700s to 1800s levels, possibly a little lower. Farmable land minus aquifer irrigated land, will be an interesting math problem for our kids.
The roll forward of progress was heavily advertised and seems orderly. The roll back is going to be completely disorganized and chaotic.
If only one of the richest and most high tech US states was nearer to some huge water source... Unfortunately it is landlocked.
Jokes aside, it won't be easy, it won't be nice, but I'm pretty sure that if it comes to it California could start desalinating the Pacific. It will provide them with something to do for all that cheap solar power that's probably going their way in 20 years or so.
Once they get the ball rolling they could even export that fresh water, if it becomes so scarce...
Global resources are finite. The resources of the solar system are finite. The visible universe is finite.
Finite is not another word for "meager."
Discussions of physical resource limits would be better if pessimistic prognosticators did not write as if finite-is-meager, and if optimistic prognosticators did not write as if plentiful-is-infinite.
Fundamental properties of nature, like the finite speed of light, preclude infinite growth. To maintain 2% annual growth in human energy consumption, in just a few thousand years we'd need to have built Dyson swarms around every star in our galaxy (and beyond). Faster-than-light travel becomes necessary to sustain that growth rate in less than 2600 years.
The BBC asked a bad question and got an obvious answer. (Maybe the badness and obviousness aren't apparent up front if you don't have a physical science background.)
Asking if fixed-percentage economic growth can continue forever is rather like asking if Moore's Law can continue forever. No, neither can continue forever. That doesn't mean that things get bad after the growth phase. Somehow both optimists and pessimists conflate "the end of growth" with "the end of prosperity." That's ridiculous, IMO. The median citizen is much better off in low-economic-growth (and negative population growth) Japan than in rapidly growing Bangladesh.
I'm sure countries in Latin America, Africa and South-East Asia are also seeing an overall increase to their standard of living over the past 30 years.
Can someone enlighten me how did he end up prediction extinction by 2300? I see words, but it makes no sense to me.
Even if it correctly peaks at 2065, even if it declines, it should stop at a stable level since most developed nations usually have 1-2 child per family today. I cannot imagine the next generations doing nothing with a laid back attitude and slowly let us die out because nobody wants to make babies :)
Even if you stay within your own solar system, a civilization only slightly advanced from our own, even without fusion power, could easily sustain a population of a trillion.
It will be interesting if the increase in automation and decrease in working hours that we're likely to see in the future will lead to a reverse in the declining birth trends that we've seen in high HDI countries.
This assumes uniform gene pools that never change. In other words, it denies evolution.
For each nation, he extrapolates various existing trends. This wouldn't be too bad if people within each nation were uniform. They are not. Given the choice between having children and having other luxury, people do not all make the same decision. The mental traits that influence this decision are inheritable, both genetically (brain structure and chemistry) and culturally (religion and more). It should be obvious that the portion of people who decide to have kids will increase. We'll be back to exponential growth until we hit real resource limits and start dying in squalor.
This is unavoidable. Anything done to stop it will be overcome, because those best at overcoming impediments to reproduction will come to dominate the gene pool.
For example, the World Bank: http://data.worldbank.org/data-catalog/population-projection...
If you look for dinosaurs, the WB also have a 1984 report on topic: http://documents.worldbank.org/curated/en/496471468156899142... (see p. 186, "Population data supplement")
The UN, IMF, and most national agencies also release their numbers.
In general, world GDP growth — and its correlates, like HDI — is stable enough to predict population growth. As a country gets richer, fertility falls: women get careers, jobs require more education for children, people start to rely on savings, instead of family. The aggregate numbers are smooth and predictable. At least, for a reasonable time horizon.
But you need to fine-tune the model at the right aggregation level. For example, the US, EU, Japan have similar GDP levels, but fertility in the US remains high. Census data helps settle down these issues.