Great harm from the population explosion has been done. The environmental damage is enormous. Yes, we can still feed ourselves but this is not the only aspect of population growth fears.
People say this all the time, but it's simply not true. There is no limit to our resources because they can be recycled endlessly. The atoms don't wear out.
The only input necessary is energy, and we are working hard to make that cheaper and cleaner.
Maybe atoms don't wear out, but neither can resources (that are not merely inter-changeable atoms) be "recycled endlessly".
You cannot "create petrol" after it runs out, for example, unless you spend more energy that you get from it, which defeats the purpose. And there are tons of minerals we use that are of limited supply and non-recycle once used.
Besides any "recycle" cycle creates byproducts that we can't pile up forever.
I mentioned energy already. If you have energy you can literally create petrol from thin air.
> And there are tons of minerals we use that are of limited supply and non-recycle once used.
No there aren't. If you think there are any then post the name of one.
> Besides any "recycle" cycle creates byproducts that we can't pile up forever.
Those byproducts are made of useful atoms, there is no reason we can not process them. It costs energy to do so, so it's not worth it right now, but that doesn't mean it will always be like that.
The Earth will never run out of resources, it can't. All you need is energy, and the universe has a stupendous amount of that, we just need to harness it.
Here's a handy list: http://www.visualcapitalist.com/forecast-when-well-run-out-o...
>The Earth will never run out of resources, it can't. All you need is energy, and the universe has a stupendous amount of that, we just need to harness it.
You started with how we can't ever run out of resources, and then you added the proviso of harnessing universe's "stupendous amount of energy" (plus finding ways to make those resources by recycling -- and in a non-lossy way at that).
In the actual world, where we don't have this unlimited tappable energy at hand at the moment (and with the limitations of energy production methods) we can very much run out of resources.
Whole lot of technological leaps to get from were we currently are to this "we tap into the universe's energy supplies with great success" and "we recycle everything" state.
But in the real world when there is a shortage people find new sources, figure out alternatives, recycle more, and tons of other things. Like I said several times: Humans create resources when they need them.
> You started with how we can't ever run out of resources, and then you added the proviso
I didn't add it, energy was explicit from the start. We don't have to harness energy from other galaxies, our own home planet has tons, and the sun has far more. The "universe" part is just to say we'll never run out even if it goes short on our planet in the distant future, ignore that part if it bothers you, it's not necessary.
> In the actual world, where we don't have this unlimited tappable energy at hand at the moment (and with the limitations of energy production methods) we can very much run out of resources.
No. We can not run out. You keep underestimating people. If we need it, we'll make it. You don't need unlimited energy, just a finite amount.
Look at water in Israel - 20 years ago they had a shortage, now, they have an abundance. Why? Because they needed it, so they figured out how to make driking water.
If we run short of energy, we'll find a new way to make it. All that is required is the the need. There are tons of untapped energy sources, many of them environmentally clean.
Why don't we tap them now? Because we don't need to. That's all.
Maybe the purpose would be to have a portable fuel with high energy density that is backward compatible with an enormous installed base of existing vehicles, fueling stations, etc.
> there are tons of minerals we use that are of limited supply
If asteroid mining becomes a reality, it's not
> non-recycle once used
I'm no chemist, but it seems that if the economic need is great enough, with only energy you'd be able to melt / vaporize just about anything and separate the atoms by mass with centrifuge.
Well, maybe not helium (which has a tendency to fly to the top of the atmosphere). It's kind of a shame we use a non-renewable resource to create balloons as decorations and toys for children, that only last a day or two.
Sure. If energy was cheap enough, you could get gold (and just about everything else) from sea water.
[1]: http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...
If we use energy in such prodigious amounts we should have no problem getting into space.
> I did specify that at this time the world can not all live like Americans.
No. Even right now we can all live like Americans.
For animals, resources are limited. What is there, is what is there.
It's not like that for human. Humans create resources if they need them. If the whole world wanted to live like Americans we could create the needed resources.
Doing so thoughtlessly creates pollution, but it's not an essential part of the process.
If the recent trend of Chinese and Indians immigrating to the U.S. continues and the decline of birth rate for U.S. Caucasians continues, by 2050 the U.S. population may roughly reflect the world population by ethnicity, i.e. equal numbers of Caucasian, African, Hispanic, Indian, and East Asians. If there's a collapse around 2050 as predicted and the world population needs to suddenly reduce from 9 billion to 500 million, such an immigration-based country with control of the world's oceans and weapons would find it easy to convince its population that citizenship is the best determiner of who survives and who doesn't. There'd probably also be some religious overtones when the U.S. government sells the idea to its people.
We're only surviving today by stealing from our future. That's what "unsustainable" means. The problem is that the future catches up with you. The fact that industrial agriculture seems to work today obscures that fact.
It's both. Herbicides wipe out soil-stabilizing fibrous root networks. Fungicides wipe out soil-stabilizing mycelial mats. Nitrogen fertilizers poison the microbial environment in healthy soil (with about a trillion organisms per cc), destroying a significant source of organic matter. Insecticides kill off the earthworms, which aerate the soil allowing it to soak rain instead of running off (taking soil with it).
Any fertilizer that's mined out of the ground is obviously transient, so the ability to have a food system without fertilizer is a Very Important Thing.
So if you want to raise cereals and vegetables, you have to choose: tillage or chemical use. The latter is much easier on the soil, even if it's not perfect.
Chemical use can be eliminated (yes, even to grow cereals!) by cultivating healthy living soil. The easiest way is with green mulches/cover crops, which serve the same thermodynamic functions but using sunlight instead of fossil fuel.
* Legumes fix nitrogen. Yep, solar powered.
* Insect predators eat pests. They're part of the food chain, so they're solar powered.
* Deep rooted plants[2] bring up minerals (essentially micro-scale mining on site in response to mineral deficiencies) and make soil. Photosynthesis, natch.
You get the idea.
I don't really have to say that an erosive food system that compromises humanity's only closed-loop habitat is a bad value, do I?
[1] http://www.rand.org/pubs/occasional_papers/OP179.html
[2] e.g. Symphytum
For example make energy cheap enough, and we can desalinate enough water to re-green the Sahara desert.
That's not something we can do today, but the future is bright, and not limited.
So all we're waiting for is "power too cheap to meter", eh? :D
Planting trees can also green deserts[1], and does so without perpetual future energy inputs from desalination. This makes sense when you realize that plants cause rain.[2] The reverse is also true - cutting down forests creates deserts.
[1] https://www.youtube.com/watch?v=reCemnJmkzI
[2] http://www.nature.com/nature/journal/v496/n7445/full/nature1...
"One thing that happened on the road to doom was that the world figured out how to feed itself despite its rising numbers. No small measure of thanks belonged to Norman E. Borlaug, an American plant scientist whose breeding of high-yielding, disease-resistant crops led to the agricultural savior known as the Green Revolution. While shortages persisted in some regions, they were often more a function of government incompetence, corruption or civil strife than of an absolute lack of food.
"Some preternaturally optimistic analysts concluded that humans would always find their way out of tough spots. Among them was Julian L. Simon, an economist who established himself as the anti-Ehrlich, arguing that 'humanity’s condition will improve in just about every material way. [This has proven to be true all over the world.] In 1997, a year before he died, Mr. Simon told Wired magazine that 'whatever the rate of population growth is, historically it has been that the food supply increases at least as fast, if not faster.'"
I am old enough to remember when the ideas in the book The Population Bomb seemed like fresh, new ideas. Decades later, the world Ehrlich and I still live in seems more like a confirmation of criticisms of the book[1] than like a confirmation of the book. Since the book was first published, I have spent many years living in Taiwan, starkly poor when I was born and still poor when the book was published, and one of the more densely populated countries of the world during most of my lifetime, but today a prosperous, delightful place to live. The population of the United States has increased greatly in my lifetime, but the United States is still a great place to live too. Fears of great harm from a population explosion were just wrong, that's all. This article is part of a great article series published by the New York Times looking back on predictions from earlier eras and how they turned out.
[1] https://en.wikipedia.org/wiki/The_Population_Bomb#Criticisms