Because the data keeps matching their Business as Usual model. I think there's more recent research, but here's a paper from 2014, showing 40 years of reasonable fit: http://sustainable.unimelb.edu.au/sites/default/files/docs/M.... If we keep matching their model, we'll soon see dramatic population declines.
Also, the patterns revealed in their models are useful for understanding patterns in nature and human interaction with it.
Just looking at Figure 1 on page 8 of the paper you mentioned, it can go either way because we haven't seen a reversal in any of the trends. That is hardly a prediction. For example, if one looks at the "Services per capita", is there any sign that it will meet an inflection point in the next few years?
I know it is always appealing to tell a story with a grand unifying narrative. But sound research must prop it up with empirical evidence. Could there be limits to growth? Probably. But a highly simplistic model not informed by appropriate data or economic understanding is not the way to tell such limits.
There have to be limits to growth, but we won’t know where they are except in retrospect. We also may never hit them due to fertility decline which occurs in all wealthy societies. Fertility decline plus efficiency increase could cause consumption of some resources to fall.
Space migration doesn’t change the equation much on Earth unless you start mining and manufacturing off world and importing product, and that is pretty far off.
"Could there be limits to growth?" Yes 100% (you cannot extract indefinitely more and more every year from finite resources), the debate is simply when we'll peak for a given ressource (20 years, 100 years, 1 million years) and the size of such an impact on the economy.
It's worth noting that world3 model is fairly sensitive to initial conditions and small perturbations can yield population predictions exceeding 20 billion or under 1 billion [0]. It's pretty unclear whether the patterns are actually useful or actually "natural" rather than artificial. For instance, virtually all scenarios in world3 end up in a peak->collapse, but it strains credulity to imagine that similarly applies in the real world.
> For instance, virtually all scenarios in world3 end up in a peak->collapse, but it strains credulity to imagine that similarly applies in the real world.
Why? Many civilizations have come and gone through the collapse cycle already. Why do you suspect we're any different? What makes you think the ecosystem can even tolerate 9-10 billion of us?
If you pick any particular definition of "collapse", very few will actually meet it (let alone on a timescale of mere years or decades). There's quite a lot of literature on this subject already (e.g. Questioning Collapse), but there's also tens of thousands of years of human history apparently lacking records of anything that could be called a collapse.
As for a specific carrying capacity for the Earth, it should be obvious how impossible such a number is to give without a lot more detail in the question. But if we were to assume 10B global population, it could be done with a population density roughly equivalent to precolumbian California. This is not to suggest that indigenous californians lived in perfect natural harmony, but rather to illustrate how low the numbers actually are. I suspect there's probably many reasonable (though utterly alien) ways of life where that density could be "sustainable". Equally, I suspect there are many ways of life where those numbers are not "sustainable".
The eocsystem we were born into as humanity would not sustain even a small fraction of the humans alive today. We modify the ecosystem until it will sustain us (or 'just us', for that matter).
What makes you think we can continue to do that? Even if we can, what makes you think we can do it sustainably? And if we can do it sustainably, what makes you think we will? History doesn't really provide any encouragement here.
Agreed. Nothing about this is normal. Not the way we live, not the way we work, not the way we take a hot shower every morning. It's highly un-normal. But because we're relative creatures and define the 'normal' by what we experience and not by what has been the normal for hundreds of millennia, we tend to misunderstand the reality of our situation.
Just to be clear, if by "normal," you're referring to the way humans existed for 95% of their existence, which was as small bands of hunter gatherers, that very clearly implies an advanced state of collapse. Even if some of the worst case scenarios for collapse come true, that's a long ways off. For one thing, it would probably imply a significantly reduced population (probably no more than 10-20% of current population levels) before nomadic hunter gatherer groups becomes an efficient way to live.
That was just an observation with regards to what we "modern" humans consider to be "normal", not a comment on how far down the next collapse will bring us.
(Not to mention that we probably have neither the abilities nor the ecosystem to revert to hunter-gatherer subsistence.)
No, I don't expect a collapse back to the stone-age in the short run. But to every human living in "modern" conditions, a reversion back 100 or even 200 years in terms of comfort and luxury will be quite staggering.
The wake up call will be a very harsh one, nonetheless.
Slowing birthrates is very far from a population collapse. It's also (to generalise vastly) desirable - slower population growth is desirable environmentally.
This is why I said "starting to." You did notice those two very important words, didn't you? Because this is how it starts.
I agree that decreasing population is desirable from an environmental POV, to the extent that population is more or less directly proportional to consumption. But, capitalism as we know it can't survive it. Here's a good explanation: https://www.axios.com/the-new-threat-to-capitalism-73ff54bd-...
> This is why I said "starting to." You did notice those two very important words, didn't you? Because this is how it starts.
"starting to" is a prerequisite, but a reduction in birth rate doesn't necessarily lead to a population collapse, and you don't seem to present any evidence that this is one of the cases where it does.
What evidence would you consider sufficient, besides globally falling birthrates?
Again, I will remind you, the comment says we are "starting to see evidence," of population collapse, not that population collapse is happening or is inevitable. Globally declining birth rates is certainly evidence that it may be happening.
Well population dynamics are pretty predictable for the next ~40 years or so.
The inputs are the number of people of childbearing age over that time period and the number of births per adult. We know the maximum number of people (since new people don't get born at ages above zero). The number of births per adult tends to change very very slowly and pretty predictably.
A population collapse would be caused by one or both of these things changing dramatically.
There's no evidence of this. Instead there is evidence of a slow decline in population as the birthrate (especially in Africa) slowly decreases.
> What evidence would you consider sufficient, besides globally falling birthrates?
Something that indicates that the current models showing a slow decline are wrong.
That money will trickle down isn't a myth. It's an outright lie or fraud. It's more clear to see when you take away the imagery and see it says: giving money to rich people is giving money to poor people.
It suggests to read at an inch or two past comfortable for a few hours a day. At first it seemed too good to be true, but not completely implausible. I'm curious if anyone has tried or had luck with it.
I'm not familiar with it and can't look into it as I'm on a slow connection right now. It sounds similar to the endmyopia method, which has been working very well for me.
Wow, I took a class from Paul Steinhardt when I was starting my PhD in physics at Penn.
I think it was in him in his class who asked us how planes flew. I raised my hand and said the Bernoulli principle. He showed how despite schools teaching it forever, it couldn't be right. Otherwise planes couldn't fly upside down but they do.
The only thing changing slower than expected is humans. We resist stopping digging and burning fossil fuels.
One thing we know reduces emissions and pollution: stop digging and burning fossil fuels. We're using every excuse not to. Everyone has their thing they want to do that delays capping the wells and closing the mines. Beyond overconsumption, we can't even talk about overpopulation without losing our shit (though a few people and nations have made great progress, see Mechai Viravaidya, for example).
You can't "just stop" unless everyone does. But if there exists any competitive advantage to cheat and not stop, then those who do will become more powerful than those who don't. There definitely exists a competitive advantage to burn cheap fossil fuels since we get to externalize and socialize the negative consequences on everyone while privatizing the gains when we do.
watch Elon Musk respond to this question on a panel talk, in front of Oil executives, in Norway .. master class in diplomacy.. hint "just stop" is not a winning position, no matter what outcome you favor
It is the ONLY winning position. (almost) Every part of the world talks incessantly about it or around it rather than actually taking the position. Saying "just stop" is only the first step and if you can't take that, you haven't realized that every other position is a losing position. The trick is that it's a worse and worse position each day.
Saying "just stop" isn't supposed to win immediately against those who will fight you regardless of what you say. It's to show you're willing to take off the steering wheel in a head to head. Ofc, you don't want to say it when you don't mean it.
I'm convinced that parts of the world, thirsty for water (and other resources) will go to war and it still will not stop. The hand wringing and peace making is unsurprising business as usual.
Yes, our beautiful little system we've constructed is starting to feel more and more like a ball and chain. We can't bother doing what's in everyone's best interest because it also happens to be in nobody's individual interest. Quite a predicament.
Elon Musk is today's Robert Moses. People associate him with helping the environment, but he's pushing for growth as his top-line strategy. He may lower emissions from tailpipes, but systemically, he's exacerbating the problems.
Elon? Is that the guy who moved to Texas to dodge taxes and regulations? Who’s expanding industry in one of the states with the least environmentally friendly laws in the nation? You know, a state where rolling coal is considered a pastime?
Yeah no thanks. I sold my Tesla shares after he took a cheap shot at Bernie Sanders (funny how he never took a shot at Donald Trump, weird huh)…
To propose we go to Mars to protect the species is backward. People with the means want to go to Mars to show off or other personal reasons. Then they drum up some humanitarian-sounding reason for government and popular support.
If we could prove beyond shadow of a doubt that no dangerous asteroids would hit Earth for a million years and that pursuing Mars accelerated our environmental problems here, I don't doubt that the same people would come up with new justifications and keep going, even if counterproductive.
The bicycle wheel. I can't believe 16 hours and nobody mentioned it (that I found anyway). You will find few things that serve their functions so well with such a minimum of material.
The General Public License. The foundation of Linux, Wikipedia, and more. Every company and government agency that took it on lost. It uses the rules it wants to subvert to subvert them.
The United States Constitution. So far it has withstood onslaughts and survived. We may be seeing the end of it, but people have said that before. It's inspired many others. The United States may be young, as cultures go, but our Constitution is, I believe, the oldest.
Like the jobs the book Bullshit Jobs referred to, I'd bet most of the cargo in these trucks is bullshit products that will end up in landfills within six months.
I understand that this is an oft-repeated meme, but what are these mountains of products that go to the landfill in six months, and who has the money to buy them?
Fast fashion, costumes, holiday decorations and props, organizational solutions, non-heirloom[0] electronics.
[0] not sure what the term of art here is, but flash drive, charger, cables, remotes, even monitors and TVs rather than designer record players, home entertainment systems etc
Generally, I think it's a mistake for anyone to generalize about the purchasing habits of millions of people, but I can list a few examples of disposable merchandise:
(Imagine most of these things costing under 5-10$)
* Toys for children that break very easily (wind up toys, small non-metal cars, plushies)
To answer your question about who can afford to buy them: In my own experience it's people who can't afford to buy better made, more expensive products. If you've ever, say, bought very cheap pair of earbuds or charging cable, and had it die in a month, that is the sort of product in question.
It might make more logical sense to "buy right, instead of buying twice", but there are times where someone is either in a jam, or can't afford to get the quality version.
None of this stuff remotely makes up 'half the products shipped internationally', by value or volume.
And just because something is cheap crap, it doesn't mean that it gets thrown out. I have seen a lot of crap cutlery in my life (when visiting friends), but I always see the same crap cutlery when I visit them. They keep it for years, because shitty as it is, it does what it is meant to. The only time it gets binned is when they replace it with a keep-it-for-life, quality purchase. Likewise for garden equipment. There's a lot of crap out there, and for most people, it suits their needs. They aren't professional gardeners, they only need these tools a few times a year.
I have a shitty toolkit. I'm not a carpenter, I'm not a mechanic, and it's all I need.
I think a possible clue would be to look at the products that pile up in peoples homes, but are essentially cast off or unused. Home space is a staging area for the landfill, if not an outright landfill.
And guilty as charged. I could go through my house and tell you the stuff that I shouldn't have bought, or that had a very short useful lifespan due to changing interests or buying ahead for things that I ended up not needing.
The turkey that would have been mine is still alive.
When I stopped eating meat in 1990, people saw it as a burden on them. Over the years, more joined the bandwagon, not that I did anything that people haven't been doing for centuries. Now if anyone seems to need to explain, it seems the omnivores, though all families are unique.
hey other dek, I've converted all sides (stuffing, potatoes, gravy, green beans, etc) to pure vegetarian. The vegetarians say what I'm making tastes great. I still haven't managed to make a stuffing or gravy without turkey stock that tastes great to me.
Today is also Buy Nothing Day for those with different values.
Our mainstream culture generally says growing the GDP helps everyone, that "a rising tide lifts all boats." Some of us see the evidence pointing the other way and avoiding needless shopping helping people more.
Also, the patterns revealed in their models are useful for understanding patterns in nature and human interaction with it.