1) The source doesn't combine Guangzhou, Shenzhen, and surrounding cities like citypopualtion.de does. Otherwise Guangzhou would be here.
2) We can be pretty confident about projections made for the next 30 years.
3) However, on this time scale, projections will probably be very inaccurate. 80 years out, population growth matters a lot. Blantyre currently has a population of around 1 million, and is projected to grow to 40 million.
Well we can be pretty sure for the next 30 years barring any major disasters or wars. So this quiz is assuming that in the next 81 years Tanzania won’t separate from the rest of Africa and sink into the ocean
But is it more probable or not that there will be a major disaster in the next 30 years? Climate disasters? Wars for (e.g. Himalayan) water supply? Wars in the South China sea for hegemony over the global trade routes? Continent-size proxy wars for resources in Africa, followed by subsequent civil wars?
@TheLastFish. It's hard to estimate, but I would say the chance of a major conflict in the next 30 years is lower than in any other 30 year period in human history. We are living in by far the most peaceful, prosperous time there has ever been. And it's not even close.
Russia's 2022 invasion of Ukraine, combined with growing talk that it wants to conquer a few more countries if it succeeds there, might change that prediction somewhat.
Nah, I say we are pretty sure things won't go as smoothly as everybody here seems to think. For once, the global warming is not going to disappear and lots of land are going to get flooded (Also there is a risk for densely populated regions depending on mountains for their water supply in the dry season). This will lead to massive exodus and global political destabilization, in turn leading to war, diseases, starvation...
The second big aspect is the oil supply : even optimistic estimates don't think the supplies will last for more than 50 years (and it is probable we are currently nearing peak oil). Without more oil supply global trade will diminish (or even collapse) thus leading to stravation and wars for resources. I'd say we can go on with business as usual for 10 years but after that nothing's too certain. But a population of 20B people is just impossible, whatever happens something will stop us to grow that big (be it ourselves, shortage on food or diseases)...
You can't be pretty sure at all. Birth rates are falling all over the world. In India they have cut in half over the past 20 years (https://preview.redd.it/the-declining-fertility-rate-of-india-2001-vs-2021-v0-2405n4tt9t1d1.png?auto=webp&s=ac4ef8943d4f8f16e6e81e93f54d0ebcd90d8452). So any prediction like this made about India in 2002 would turn out totally wrong in just 20 years time. No reason to think any of this is remotely accurate.
Another example, New York (the only North American city) has a TFR of 56%/1000 which is about 1.5. So it's population growth is driven entirely by immigration, which also makes up the .6 deficit. No reason to believe this is sustainable enough over 80 years to raise the population by another 22 million people.
These kind of predictions just take current birth rates and then extend them logarithmically into the future without taking into account any extenuating factors.
It's an interesting exercise (both the quiz and the underlying research), but even the paper the source list is based on recognizes that the projections about Sub-Saharan Africa in particular are implausible:
"Projecting city growth, typified by Lagos growing from 10.6 million in 2010 to 88.3 million in 2100, calls for a healthy measure of scepticism; many variables could change. Projections used here are linked to the 2050 WUP city estimates that, especially in Africa, are suspect, and here these projections are extended for yet another 50 years, suggesting caution in their use. . . . Niamey, Niger for example is projected to grow from under 1 million inhabitants today to 56 million in 2100. Growth rates like these appear overstated, especially in one of the world’s poorest countries with an insufficient economic base to support this rate of urbanization."
(The updated paper is here: https://journals.sagepub.com/doi/full/10.1177/0956247816663557)
Go back 50 years and predict "Lagos will have 18 million people by 2019". No doubt the same objections would be raised and yet, here were we. While the future will likely be different in unfathomable ways, the null hypothesis is to assume that current trends will continue.
Sure, but it's unrealistic. When a car goes at maximum speed into a wall, the null hypothesis says that the car is going to continue going at full speed, but in reality the car is going to crash against the wall...
For Lilongwe in geographically tiny, landlocked Malawi to reach 40 million people it would require political union with a larger country or development into a trading dynamo like strategically situated Hong Kong and Singapore.
I mean seriously these numbers must assume political or economic changes, with which would probably come reduced natural increase.
That's what I thought! They got it from this wikipedia article in the 2100 cities population column: https://en.wikipedia.org/wiki/Projections_of_population_growth
Yeah. Are 2 of the 15 largest cities in the world *really* going to be in Malawi? If you look at what Wikipedia says, it has both of their populations rising from ~15 million in 2075 to ~40 million in 2050--a total increase of 50 million people in these cities over just 25 years! I know these projections are probably very inaccurate, but still the idea that this *could* happen astonishes me.
Looks like the source loves business as usual scenarios...But then they have to take at the very least the devasting consequences of climate change into account. A more plausible estimation for Lagos, Dhaka, and alike is then < 1 Mio except we start to contruct submarine cities.
Maybe in the year 2500. Worst case scenarios call for a 3 foot rise in sea levels by 2100. Climate change is bad, but humans will adapt. Pity the other species who won't be so fortunate.
You discount the degree to which we rely on all those other species in ways we haven't begun to understand. Homo Sapiens is part of the planetary ecosystem and less able, imo, to exist separately than we like to think. Some part of us may well become a new species, but h. Sapiens will not survive unless we can preserve a substantial portion of the biological world in which we evolved.
I think the aspect of climate change that will hinder the growth of these massive metropolises is more likely to be drought than sea level rise. A good number of them are located in the desert, and also the desert is expanding....
But imagine Niamey on the edge of the Sahara Desert, from 1 million now to 56 million by 2100 then on to 600 million by 2200. A report on Niamey says that the women in Niamey that have to collect wood for cooking etc. rarely have to venture more than a few kilometres to collect enough for the day ...... fun times ahead.
How is it possible that no Chinese cities are on this list? Where is Beijing, Shanghai, Guangzhou (even without citypopulation.de's stupid combination)? And how are none of these larger than Saigon?
That may be true and may not. While sea level rise is clearly on the horizon, it's very uncertain how fast it will happen (and thus how much land will be inundated by whatever time). The main point, though, is correct in that it challenges the apparent clarity of these projections. It's pretty ridiculous to project Dhaka's population with any certainty. Zero might be as good a guess as any.
Jakarta is in danger of flooding and it's already visible every year when the rain comes, which varies from 70 to 125 inches a year throughout the country’s lowlands, the floodwaters have nowhere to go. And the city floods every year; 13 rivers run through it, and best believe they fill up with water. This is also the reason why they've plans on moving their capital to Palangkaraya on Borneo.
Finally someone gets it. Although, in my opinion existential risk due to the creation of strong AI is probably greater than that due to climate change. We already know how to stop climate change (we just lack the will). If we create strong AI, there will be no way to stop it except to hope that is is nice to us.
What ridiculous methodology. Demography reduced to mathematics. They do nothing but take past trends, map them onto current populations, and do the calculations. It reminds me of projections for the population of Mexico City back in the late '70s and early '80s. But why believe me - from the brief article itself: "Projecting city growths typified by Lagos growing form 10.6 million in 2010 to 88.3 million in 2100 obviously call for a fulsome measure of skepticism; many variables could change."
Just to play devil's advocate Nigeria's population in 2010 was 10.6 million as you said, but now in the beginning of 2021 it is already 14.8 million and the growth has increased every year and is projected to increase for a very long time in the future. The question really is if something major is going to happen to decrease the population and what is the carrying capacity in the area. If Lagos develops while the population increases it could be possible to sustain a very large amount of people (although I agree 88.3 million probably won't happen).
Scary...so may ppl will be born into a world with few rights and no assets. It is hard to believe that we can maintain a decent life with clean water and food. What will happen to the forests and the oceans? Plus soil erosion...
Yes, but ... I used to live in rural Sichuan in China about 20 years ago. People in general were subsistence farmers, whose average income per year was about $100 US. Nevertheless, the pollution was mind-boggling. There were days when you could not see across the street. Rivers ran some pretty strange and unnatural colours. I would wonder how they were getting that level of pollution when the average person had nothing.
Even if the birth rates of the countries are low, it doesn't mean the cities will shrink at such a rate. Migration from small towns and cities to China's bigger cities is quite likely. Guaranteeing that some of these cities would rank surely.
Its not just that the birth rates are low, its that they are expected to continue decreasing. Migration won't be able to overturn the sharp decrease in NIR (Natural Increase Rate) we will see in these cities in the near future (let alone in 80 years).
Look at the predictions made for San Francisco when the Gold Rush hit or Detroit at the peak of the Car production or Moscow when the Soviet Union was growing, cities will grow and shrink, rise and fall. Growth rates rarely remain in place for decades. After a war people return and growth rates go through the roof (Baghdad, Kabul), which can change in a heart beat. Africa will no doubt grow, but maybe we'll see Vietnam surge or Turkey rejuvenate, even Saudiarabia may change drastically and produce a mega-city. Who knows...
Having been to many of these cities I'll just take 'Niamey' for example. The population is approx. 1 million now and many have no potable water, scrambling for food, no paying jobs etc. How will they have a population of 56 million in 80 years? ....... Can someone tell us how this miracle is to be achieved?
I just dont think many of these places are sustainable. Sana´a? The countries been at war for years, is in a desert, and as the war continues and global warming gets worse, oil starts running out, I just don't see it happening
I think that Niamey will indeed be able to grow this much. Niamey has an urban area that is HUGE. 30 percent of that is desert, a growth in population = a GDP explosion, which Niger can use to develop Niamey to make it capable of having that many people.
This is flawed as it only looks at current population growth. It doesn't take demographic transition into account. https://en.wikipedia.org/wiki/Demographic_transition
These are predicted numbers. But very unlikely numbers. It would be near impossible to sustain populations these sizes in cities like Niamey and N'djamena. They would have to import nearly all their food, since these are poor agricultural areas.
30 million people in NYC? No there won't be, they'll flee to other states like Florida, Texas, or nearby Jersey. To the above points, the climate doesn't even have to change. More people than ever, not just in bulk but as a percentage, live along the coast. All weather has to do is repeat events of the past and catastrophe rates will be much higher. Also, the quiz doesn't account for the number of people that I believe will be eaten by manbearpig and other related species in the years to come.
honestly, how on earth are two cities in a landlocked country in southern Africa predicted to have a population more than cities like Johannesburg and Cape Town, cities that have thousands of square miles to grow to house a lot of people!
Anyone doubting this, imagine telling someone in 1700 New York today's New York population. Surely it wouldn't happen, and if it did, it would just be the would be the same wooden houses. That's what the colonist would think.
It'll happen and it'll prolly be possible and developed.
Just curious...why is this quiz necessary to complete the Cities Badge?
This one feels more subjective and like it doesn't quite merit inclusion in the badge category. Of course, I might not feel like that if I could just hit that magical number of 25...
1) The source doesn't combine Guangzhou, Shenzhen, and surrounding cities like citypopualtion.de does. Otherwise Guangzhou would be here.
2) We can be pretty confident about projections made for the next 30 years.
3) However, on this time scale, projections will probably be very inaccurate. 80 years out, population growth matters a lot. Blantyre currently has a population of around 1 million, and is projected to grow to 40 million.
The second big aspect is the oil supply : even optimistic estimates don't think the supplies will last for more than 50 years (and it is probable we are currently nearing peak oil). Without more oil supply global trade will diminish (or even collapse) thus leading to stravation and wars for resources. I'd say we can go on with business as usual for 10 years but after that nothing's too certain. But a population of 20B people is just impossible, whatever happens something will stop us to grow that big (be it ourselves, shortage on food or diseases)...
These kind of predictions just take current birth rates and then extend them logarithmically into the future without taking into account any extenuating factors.
"Projecting city growth, typified by Lagos growing from 10.6 million in 2010 to 88.3 million in 2100, calls for a healthy measure of scepticism; many variables could change. Projections used here are linked to the 2050 WUP city estimates that, especially in Africa, are suspect, and here these projections are extended for yet another 50 years, suggesting caution in their use. . . . Niamey, Niger for example is projected to grow from under 1 million inhabitants today to 56 million in 2100. Growth rates like these appear overstated, especially in one of the world’s poorest countries with an insufficient economic base to support this rate of urbanization."
(The updated paper is here: https://journals.sagepub.com/doi/full/10.1177/0956247816663557)
I mean seriously these numbers must assume political or economic changes, with which would probably come reduced natural increase.
It reminds me of end of 19th century predictions of the amount of horse manure for the upcoming 20th century...
Lagos (2100): Hold my beer
But seriously, it would be awesome to look at this quiz again in 2100 and compare.
yes I am from kabul
Can I translate the Quiz to German?
It'll happen and it'll prolly be possible and developed.
This one feels more subjective and like it doesn't quite merit inclusion in the badge category. Of course, I might not feel like that if I could just hit that magical number of 25...
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