Like the illusion of Wall Street, with its vast and powerful investment banks, now shuttered, China too is an illusion perpetuated by the Globalists that gave us the 15,000 mile Caesar salad, poisoned cat food and lead based paint on babies' pacifiers. Like the illusion that money would come from thin air to always push housing prices higher, China has spent a generation pursuing its illusion. Pursuing an unattainable dream to be like the West, while 6000 years of its carefully shepherded top soil blows into the sea.
Joined: Sep 14, 2004 Posts: 6625 Location: Rural Virginia
Posted: Wed Feb 13, 2008 8:57 am Post subject: Re: Carrying capacity
careinke wrote:
Perhaps you are looking at this from the wrong end? Maybe we need to figure out the minimum amount of arable land required per person.
I am pretty sure I could support 5 people on ten acres indefinitely. I could probably do it on 7 acres, if I did not have to pay taxes (Property, excise, sales etc).
This would include building materials, heat, all food and clothing production. With some left over to trade with other people.
So two acres per person of arable land. I'll leave the math for you to figure out how many people the earth would support.
Cliff (Start a rEVOLution, grow a garden)
It doesn't work that way.
There are eco-connections and complex natural systems that extend well beyond the borders of your two-acre plots. Occupying the entire arable surface of the earth with people in the way you describe would still result in severe environmental degradation over time, and continued species loss.
Also, people move around. They congregate. They concentrate their damage in key areas. They damage other areas in addition to their home areas. You're not going to be able to confine each person to his or her two acres.
We need to maintain large, wild areas that are free of people and that remain undisturbed as much as possible. We must increase in size, not continue to peck away at, the wild areas that yet remain.
We need to address human numbers, too. That's the side of the equation no one dares consider, but it's the most crucial side. Until we seriously look at controlling population size, we're just blowing air in our eco-discussions and "green" initiatives. _________________ "Actually, humans died out long ago."
---Abused, abandoned hunting dog
"Things have entered a stage where the only change that is possible is for things to get worse."
---Me and my brother
Joined: Dec 27, 2004 Posts: 13183 Location: naive idiot fantasy world
Posted: Wed Feb 13, 2008 10:12 am Post subject: Re: Carrying capacity
Heineken wrote:
We need to maintain large, wild areas that are free of people and that remain undisturbed as much as possible. We must increase in size, not continue to peck away at, the wild areas that yet remain.
I agree. This is also the primary goal of Permaculture, to return most land to wild nature, for the health of the Earth and the human species. To do this we must limit our population and consumption. _________________ "...powerdown so soft and fluffy you'll think you're living in a pillow." - jboogy
Posted: Wed Feb 13, 2008 11:08 am Post subject: Re: Carrying capacity
seldom_seen wrote:
ekaggata wrote:
But what I'm really trying to get to is that I think carrying capacity is always a function of available energy.
Remove oxygen and carrying capacity will be reduced to 0 regardless of the amount of nuclear reactors or oil wells.
But one of the key points I was trying to make was that, in the case where there is a limit based on a particular chemical element or compound, it could be theoretically synthesized through nuclear transformation.
In the case of elements lighter than iron (such as oxygen), I have to admit that this is a massive stretch beyond present day technology, because such elements would have to be created by fusion.
So if there is any true limit based on total amount of oxygen (I know too little of climate science, bioscience and Earth science to be on solid ground with this one) then you have a fair point.
But I haven't heard people argue based on oxygen limits before. It sounds very dubious to me based on a) oxygen is being cycled and b)there are huge amounts of oxygen in the crust anyway in oxide form.
Quote:
I think possibly your background in nuclear engineering and/or mathematics has caused you to to try to encapsulate carrying capacity in to a sort of logical problem that may possibly be solved with the correct mathematical formulas. In orther words, you have come to recognize how buggard we are and would like to see us engineer our way out of this mess. I understand where you're coming from.
You're absolutely right I'm coming at it from the mathematician/physicist/engineer angle, and I accept that this can't be the whole story. However I'm not trying to "encapsulate it into a logical problem" so much as trying to apply logic to find the genuine limits (limits that are not merely of imagination or technology).
Quote:
We don't have an engineering or math problem though. It's a biology problem.
If you want to argue that the limits can only be found in what is biology and not physics or chemistry, then you have to be super-clear about what that is. What about biology is not reducible to the laws of chemistry (which are reducible to the laws of physics)?
Quote:
Millions upon millions of people using up resources as fast as they can while humping each other like mad and making exponentially more babies who want HDTVs, steak dinners and ipods. A new fleet of fusion reactors would only exacerbate this problem. Covering the mojave desert with solar panels will make it worse.
It would be absurd for me to argue that a fleet of fusion reactors could support exponential growth indefinitely. But exactly how much humanity could be supported in this way? 0.5 billion? 10 billion? 1 trillion? At least we can talk about orders of magnitude, if we have a real handle on what actually drives carrying capacity.
Newfie,
Thanks very much for the example of how footprint is calculated. Interesting site. I took a look at the spreadsheet "GFN_Footprint_Biocapacity2006.xls". It seems they break down the footprint into many sections such as "Cropland", "Carbon", "Fishing ground", "Nuclear" etc.
Surely all of these calculations are dependent on a massive raft of assumptions about how we use energy and ... well just endless assumptions. Why not assess the solar ecological deficit? The carbon deficit is measured how, exactly? Based on a model of climate change? The use of cropland varies tremendously in productivity, how soil is affected etc etc.
I can't see how this is actually going to give reliable answers as (if) technology drastically changes.
Joined: Oct 04, 2004 Posts: 5715 Location: Body in OK, Heart in TX
Posted: Wed Feb 13, 2008 11:23 am Post subject: Re: Carrying capacity
I think I understand where ekaggata is coming from. I agree that it may be theoretically possible to engineer our way out of things like phosphorus depletion, terraform the atmosphere if we kill off the phytoplankton, etc. Aside from the quite valid practical problems with such things, I see the complexity of the system as the physical limit to what we can do. Heineken, Ebyss and Ludi are right, we are dependent on the health of the biosphere as a whole, and we will never be able to engineer anything as resilient and healthy as what evolved naturally. I don't know of a way to quantify the limit, though. If we were capable of modeling the system well enough to quantify that limit mathematically then we could perhaps achieve the engineering necessary to overcome it. _________________ "Every junkie's like a setting sun..." - Neil Young
Posted: Wed Feb 13, 2008 11:27 am Post subject: Re: Carrying capacity
FreakOil wrote:
Even if you could recreate an organism from scratch, what would you do with it? There's more to an ecosystem than just a list of necessary species; there are varying populations of specific species, with members of species interacting and entire populations of species interacting in myriad ways.
One factor to consider is availability of food. When there's less food, the population of a species that feeds on that food would decrease. And that's just the beginning. The biosphere is not a jigsaw puzzle. It's much more complex. You can't just insert species.
Not to be flippant (or maybe to be flippant ), but what if you created a Frankenspecies?
This discussion reminds me (and I hope I'm not being too obscure here) of the fact that when men first tried to find a way to fly they emulated birds by attaching wings with feathers to their arms. Hundreds of years later they realised that if a man wants to fly, he does not have to copy what nature already provided and indeed is wasting his time attempting it.
If it is in some way necessary for humanity to replace functions which die out in the ecosystem, it will probably be done in a radically different way.
As I said in my first post, I think the idea of "nature as stasis" is a pervasive myth. There is no stasis, just as is there is no central point on the Earth's surface or in the Universe.
By the way there is some kind of ecology professor in the US who has made this point in some book or other. I'll try to dig up a reference.
PS I do realise that "replacing functions in the ecosystem" sounds a good bit too ambitious right now (monkeys with handgrenades ...), but I'm talking about very long term changes.
Posted: Wed Feb 13, 2008 11:29 am Post subject: Re: Carrying capacity
Heineken wrote:
We need to address human numbers, too. That's the side of the equation no one dares consider, but it's the most crucial side. Until we seriously look at controlling population size, we're just blowing air in our eco-discussions and "green" initiatives.
I think a lot of us are "daring to consider" precisely this. It is precisely because I believe we have a moral imperative to avoid massive and rapid die-off that I would like to actually pin down whether there is any scientific evidence that a die off is actually inevitable from here. Hence this thread.
Posted: Wed Feb 13, 2008 11:42 am Post subject: Re: Carrying capacity
EnergyUnlimited wrote:
I am quite surprised that this thread didn't turn into a flame war yet.
There were few such threads here in the past and they invariably did.
Yes. Politeness is really important on the internet
Quote:
Anyway Ekagata is asking us to name a particular factor, which is certain to put limit on human population as per Liebig's law.
That is rather impossible task as factors are interdependent and can work in non linear synergistic fashion, as they usually do.
Although this is on the face of it perfectly reasonable, don't forget that this is precisely the point Liebig tried to address. There is always one limiting nutrient, albeit it can be supplanted if a new supply of that nutrient is found.
Quote:
Arguments that there are no limits as long as arbitrary amounts of energy are available are of academic value only (means of no value at all).
I disagree. Their value is that they frame the discussion properly. But sure, there are many (very plausible or likely) scenarios in which the overarching importance of energy at a theoretical level will be trumped by practical realities (politics, lack of technology etc.)
Quote:
However I will try to pin point one single factor which is very likely to put limits on number of humans, should all other constrains have failed (and they will not fail btw).
That is depletion of high bioavailability phosphorus from topsoil.
So with the progress of time phosphate fertilizers will be less and less available due to high grade phosphate rock depletion and yields are bound to fall.
Low grade phosphates cannot be converted into sufficient amounts of high bioavailability fertilizer due to basic chemical constraints.
And if you crush that rock and use it as fertilizer directly then yield will still fall due to low bioavailability of such fertilizer.
So once you run out of phosphate fertilizer, you will no longer be able to maintain current 6.7 billions.
Before green revolution you couldn't.
Thanks for bringing this up. This is one of the very few concrete examples I've already heard of and it sounds very plausible. I will avoid mentioning nuclear transformation into phosphorus (pretty ridiculous right now )
Can you give me some handy links that explain some of the biology/chemistry behind this problem? I have very little knowledge - I know there's a nitrogen cycle, is there not also some kind of phosphorus cycle? I mean, where does it all go?
Joined: Dec 27, 2004 Posts: 13183 Location: naive idiot fantasy world
Posted: Wed Feb 13, 2008 3:44 pm Post subject: Re: Carrying capacity
ekaggata wrote:
I believe we have a moral imperative to avoid massive and rapid die-off
This is a problem which may be addressed from several directions at once. One direction, the one which interests me the most, is the restoration of damaged carrying capacity and efforts toward limiting the amount of land needed for human support. Some people think the amount needed is much smaller than what we currently use (currently something like 40%). Many of our current practices, such as plough agriculture and pastoralism (grazing animals), greatly damage the carrying capacity of the land and lead to desertification. It's not that there are simply too many people, but that the way we live, the choices we make, are extremely damaging. (not saying I don't think we're over populated, I think we are) So before we pin our hopes on magical technology, we might consider using known technology to change the way we treat the land, and how much we use, reducing it to the minimum we actually need, which is likely to be much smaller than what we currently use. _________________ "...powerdown so soft and fluffy you'll think you're living in a pillow." - jboogy
Joined: Dec 27, 2004 Posts: 13183 Location: naive idiot fantasy world
Posted: Wed Feb 13, 2008 3:53 pm Post subject: Re: Carrying capacity
ekaggata wrote:
I have very little knowledge - I know there's a nitrogen cycle, is there not also some kind of phosphorus cycle? I mean, where does it all go?
Phosphates come from rock, and leach from the soil, eventually ending up in the ocean, where in large concentrations it can kill marine life.
Our current method of agriculture requires large amounts of phosphate to be applied to the soil and wastes a great deal because it leaches out of soil which does not contain humus. Changing to methods of agriculture which preserve humus would help preserve the limited supply of this material. _________________ "...powerdown so soft and fluffy you'll think you're living in a pillow." - jboogy
Joined: Mar 04, 2007 Posts: 504 Location: Hong Kong
Posted: Wed Feb 13, 2008 10:11 pm Post subject: Re: Carrying capacity
Ludi wrote:
ekaggata wrote:
I believe we have a moral imperative to avoid massive and rapid die-off
This is a problem which may be addressed from several directions at once. One direction, the one which interests me the most, is the restoration of damaged carrying capacity and efforts toward limiting the amount of land needed for human support. Some people think the amount needed is much smaller than what we currently use (currently something like 40%). Many of our current practices, such as plough agriculture and pastoralism (grazing animals), greatly damage the carrying capacity of the land and lead to desertification. It's not that there are simply too many people, but that the way we live, the choices we make, are extremely damaging. (not saying I don't think we're over populated, I think we are) So before we pin our hopes on magical technology, we might consider using known technology to change the way we treat the land, and how much we use, reducing it to the minimum we actually need, which is likely to be much smaller than what we currently use.
I agree with Ludi. I think we need to find a new way to inhabit the land. We need to turn the land back into a living, productive ecosystem rather than a linear system of chemical inputs and crop outputs. I'm highly against engineered solutions because even in relatively simple forms, they've ended up with horrible unintended consequences.
One example I like to use, and it may not seem relevant in a discussion of carrying capacity, is the Three Gorges Dam in China. The concept is simple: Build a big dam to control flooding, improve shipping and provide electricity. But look what it's brought about: soil erosion, collapsing hillsides, destruction of agricultural land, river silting, an internal refugee crisis, tremors and possibly even an earthquake.
So I don't fancy any plan for taking organisms in and out of the biosphere or turning lakes and rivers into hydroponic cultivars or any of that stuff. The key is to get back to nature - and bend linear systems back into circles. _________________ "We shall live in interesting times, and we shall die in them too." - Heineken
Joined: Sep 14, 2004 Posts: 6625 Location: Rural Virginia
Posted: Wed Feb 13, 2008 10:13 pm Post subject: Re: Carrying capacity
ekaggata wrote:
Heineken wrote:
We need to address human numbers, too. That's the side of the equation no one dares consider, but it's the most crucial side. Until we seriously look at controlling population size, we're just blowing air in our eco-discussions and "green" initiatives.
I think a lot of us are "daring to consider" precisely this. It is precisely because I believe we have a moral imperative to avoid massive and rapid die-off that I would like to actually pin down whether there is any scientific evidence that a die off is actually inevitable from here. Hence this thread.
By "no one" I mean "no one who counts." That is, no one, and no institution, with real power to influence behavior (assuming it can be influenced at all) on a broad scale.
Do you think Obama, one of the most progressive candidates in history who actually has a good chance of occupying the White House, is going to start preaching the need for population control? No way. Never. On the key issues, he fails utterly, like all of them do.
The population-control issue is hopeless. It's all hopeless. That's why we're doomed to experience massive dieoff. _________________ "Actually, humans died out long ago."
---Abused, abandoned hunting dog
"Things have entered a stage where the only change that is possible is for things to get worse."
---Me and my brother
Joined: Aug 03, 2007 Posts: 4590 Location: Boston Suburbs
Posted: Wed Feb 13, 2008 11:21 pm Post subject: Re: Carrying capacity
Heineken wrote:
The population-control issue is hopeless. It's all hopeless. That's why we're doomed to experience massive dieoff.
Well, it's possible that GW could be enough of a catalyst to make changes that could have a byproduct of mitigating peak oil. The two problems are related and Obama (or any Democrat) will address GW far more aggressively than any republican.
I also think that if a dem is in the whitehouse when the crap hits the fan that he will be more likely to respond constructively than through resource wars, you know, having the fireside chat to tell everyone they've got to commit to 80+ years of depression-era lifestyle while we all voluntarily reduce the population otherwise we're f'd.
Posted: Thu Feb 14, 2008 3:12 am Post subject: Re: Carrying capacity
Ludi wrote:
ekaggata wrote:
I have very little knowledge - I know there's a nitrogen cycle, is there not also some kind of phosphorus cycle? I mean, where does it all go?
Phosphates come from rock, and leach from the soil, eventually ending up in the ocean, where in large concentrations it can kill marine life.
Our current method of agriculture requires large amounts of phosphate to be applied to the soil and wastes a great deal because it leaches out of soil which does not contain humus. Changing to methods of agriculture which preserve humus would help preserve the limited supply of this material.
Nevertheless, yields would have to drop to those before green revolution.
This implies that 6 billions + would not have a chace to survive.
Posted: Thu Feb 14, 2008 3:50 am Post subject: Re: Carrying capacity
ekaggata wrote:
Quote:
Arguments that there are no limits as long as arbitrary amounts of energy are available are of academic value only (means of no value at all).
I disagree. Their value is that they frame the discussion properly. But sure, there are many (very plausible or likely) scenarios in which the overarching importance of energy at a theoretical level will be trumped by practical realities (politics, lack of technology etc.)
With arbitrary amounts of energy you could make arbitrary amount of baryonic mass (E=mc2 holds), convert it to arbitrary amounts of chemical elements and stuff those into arbitrary amount of new universes which could in turn support arbitrary numbers of humans.
In any case such considerations are academic and useless for all practical purposes.
Quote:
Thanks for bringing this up. This is one of the very few concrete examples I've already heard of and it sounds very plausible. I will avoid mentioning nuclear transformation into phosphorus (pretty ridiculous right now )
Phosphorus is actually quite abundant but not in high bioavailability form.
This means, it is bonded in plenty of minerals of very low water solubilty.
Essentially yet another very abundant element, calcium, is scavenging phosphorus and locking in up in highly insoluble material, calcium phosphate.
There is no low or high tech fix around this problem.
Quote:
Can you give me some handy links that explain some of the biology/chemistry behind this problem? I have very little knowledge - I know there's a nitrogen cycle, is there not also some kind of phosphorus cycle? I mean, where does it all go?
There is such a thing like phosphorus cycle, but it is slow to the extreme.
So any soluble phosphate not captured by life will be washed to high seas, converted into insoluble calcium phosphate, fall on ocean bottom, form sediment rock which is then redistributed back on the land, thanks to plate tectonic etc.
Rock is then weathering and phosphate particles distributed with wind to top soil.
This "natural" phosphorus is still in low solubility form, but nevertheless can be very slowly captured by plant roots and speed of this process dictate maximum sustainable speed of plant growth and density of plant vegetation.
Few decades ago peoples started propping up the process by crushing quite rare rich phosphate rock, sulfuric acid treatment of this, which results in highly soluble, means readily bioavailable phosphate, which is used as fertilizer.
However, as the product is taken from land phosphorus also is. On the top of that most of phosphate is simply washed to rivers, not captured by plants.
Phosphorus taken out of land is excreted with urine and also ends up in river.
Then it ends up on the ocean floor as calcium phosphate. After 200 or 300 millions of years it will be back in circulation again available for life.
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), but what if you created a Frankenspecies?
