A Matter of Time

[foodchain]

"These two last ideas are key, since they make it possible to evaluate the load capacity -- the number of organisms which can be supported by a given ecosystem. In any food network, the energy contained in the level of the producers is not completely transferred to the consumers. And the higher one goes up the chain, the more energy and resources is lost and consumed. Thus, from an energy—and environmental—point of view, it is more efficient for humans to be primary consumers (to subsist from vegetables, grains, legumes, fruit, cotton, etc.) than as secondary consumers (from eating herbivores, omnivores, or their products, such as milk, chickens, cattle, sheep, etc.) and still more so than as a tertiary consumer (from consuming carnivores, omnivores, or their products, such as fur, pigs, snakes, alligators, etc.). An ecosystem(s) is unstable when the load capacity is overrun and is especially unstable when a population doesn't have an ecological niche and overconsumers.

The productivity of ecosystems is sometimes estimated by comparing three types of land-based ecosystems and the total of aquatic ecosystems:

The forests (1/3 of the Earth's land area) contain dense biomasses and are very productive. The total production of the world's forests corresponds to half of the primary production.

Savannas, meadows, and marshes (1/3 of the Earth's land area) contain less dense biomasses, but are productive. These ecosystems represent the major part of what humans depend on for food.

Extreme ecosystems in the areas with more extreme climates -- deserts and semi-deserts, tundra, alpine meadows, and steppes -- (1/3 of the Earth's land area) have very sparse biomasses and low productivity

Finally, the marine and fresh water ecosystems (3/4 of Earth's surface) contain very sparse biomasses (apart from the coastal zones).

Humanity's actions over the last few centuries have seriously reduced the amount of the Earth covered by forests (deforestation), and have increased agro-ecosystems (agriculture). In recent decades, an increase in the areas occupied by extreme ecosystems has occurred (desertification)."

 

This is a section of text from wiki, in which I find many conflictions with my view of things. First of all, I think it basically states some derived or driving evolutionary process that simply may not exist, or at least not as worded. I think the only way it could exist is via natural selection, in which I find possibly a very viable option in regards to the environmental impact that humans are bring to the earth. Second, our omnivore status plays a huge role not only in our biology but our evolution in memory serves. The idea that humans can get by now being simply vegetarians may be true, but as hunter gatherers or cavemen I simply cant see us taking in enough protein to sustain really, though again in a modern sense is where I find the confliction, in environmental impact that is. I derive that natural selection is really a constant, and in time, organisms in relation to environment either make it or don’t along with adaptation. I think this is where you can find rapid environmental change of enough pressure brings on massive extinction. The confliction is how this is going to play out for people. I mean for however long people have been on the earth we as a specie lived a far simpler life for a majority of that time, it does not though speak of say another 4,000 years for instance. I mean you look at some specie of insect, and wow, they sure have persisted, but that organisms biology does not reflect nearly as our own does, and each specie I would imagine is a separate case under natural selection overall in a ecological sense really.

 

So what are your thoughts, do you see a positive future for humans, and how would we reach it really?

 

http://en.wikipedia.org/wiki/Organism

[swansont]

If we use the secondary products of animals that feed on things that we can't eat (like grass) I don't see that as much of an issue. But when feed is also something we can eat (e.g. grain), that's inefficient. I wouldn't be surprised to find that developed countries eat more beef/fowl/fish than they really need to.

[foodchain]

If we use the secondary products of animals that feed on things that we can't eat (like grass) I don't see that as much of an issue. But when feed is also something we can eat (e.g. grain), that's inefficient. I wouldn't be surprised to find that developed countries eat more beef/fowl/fish than they really need to.

 

I think that’s somewhat the problem. I mean not to contradict freedom or liberty or anything, but you don’t see giant debates denouncing gravities control over the natural world, but yet you do have such with these issues and why?

 

I mean you as a physicist or a student of or someone with some pretty accurate knowledge of such alone probably realize that the world has some natural order to it, such as mechanical or thermal, and well organisms and societies belonging to this I would wager to say that we or life is not a separate item overall.

 

I mean just studying what we know of geologic time, or eras such as the Cambrian we can see easily the interconnections of life and the environment. Yet today for the most part such as connection is treated for the most part as non existent, I simply don’t understand. The reality as I see it is simply destroying the microbial scale life is soil alone would probably be enough to basically devastate a majority of land based life if such was to rapid. Let alone the overall destruction of soil period which would surely bring extinction to a majority of land based life. Its simply that biology seems to me, as I learn about such, has a pretty strong grasp of the physiochemical basis of life from a molecular to an ecological sense, yet such is basically ignored, on that same note though, you wont see people simply brushing gravity aside when building an aircraft or a building for that matter, and to be honest I simply don’t understand why this is, it truly has to be an issue rooted in social science.

[SkepticLance]

The rules of basic ecology are often somewhat bent by humans. We are able to increase food production beyond what any 'natural' omnivore could hope to access. We do not even need soil. Hydroponics is startlingly efficient. Even in obtaining animal protein, we are capable of massive production. A Tilapia pond in Asia produces more animal protein per acre than could ever possibly be done in nature.

 

For these reasons, we need to be a bit cautious in applying ecological rules to human society. We are not immune to those rules, but can bend them often to a surprising degree.

[MolotovCocktail]

Well, its not so much bending the rules of ecology as it is being able to control the factors that determine our survival, such as food supply. Humans have been able to do this for tens of thousands of years. The Agricultural Revolution was just another innovation that greatly increased our control over those factors.

 

The problem is the fact that today's agricultural methods are very destructive, and inefficient as Swansont pointed out. Unlike more traditional methods, our methods destroy biodiversity, lower the nutritional value of the food we eat, and contribute to the depletion and pollution of our natural resources.

 

I'm not sure how it works in other countries, but in the US most of our production of food is industrialized, right down to its growth. Our plants are grown in huge mono-cultures that spread out for hundreds of square miles. Because they are mono-cultures, they require an enormous amount of pesticides to ensure that they aren't eaten by bugs or microbes. Mono-cultures are also very fragile ecologically since they are only one kind of plant. With livestock they are injected with various hormones to increase their size and it is uncertain what kind of effect those chemicals have on human health in the long run.

 

I remember attending a lecture on Agro-business not to long ago and they talked about the environmental impact and health impact. First of all, a lot of our food such as potato chips to drinks and even ketchup are made from corn! Of course, you would have figured this if you looked at the ingredients. Also, the variety and diversity of foods that was available before the second world war (before they industrialized food production) no longer exists. That means that some of the foods our grandparents may have eaten are no longer available for us to eat, and hence the availability of food itself has decreased because we killed off many other food sources.

[SkepticLance]

To Molotovcocktail.

 

I disagree on what you say about lack of food variety. I eat far more variety today than I did as a boy 50 years ago.

 

Also, life spans continue to increase. The best is women in Japan (86). 20 years ago, their expectancy was only 80. Life expectancy in all OECD countries continues to rise, and I am sure that the access to a wider variety of foods is one factor.

[MolotovCocktail]

To Molotovcocktail.

 

I disagree on what you say about lack of food variety. I eat far more variety today than I did as a boy 50 years ago.

 

If you mean variety as in number of flavors, preparation of food, then yes there is more variety in that respect. When I talk about variety I'm talking about genetic and biological diversity of our food. First off, a lot of foods we eat come from gigantic mono-cultures and this is bad because there is no genetic diversity among our crops, meaning that it is ecologically frail. Also, as I stated before, a lot of the food we eat or the juices we drink are made from basically the same ingredients. To prove my point, consider two completely different types of food: Ketchup and cereal.

 

Ingredients of Heinz Brand Ketchup:

Tomato Concentrate made from red ripe tomatoes (Whatever that means...), Distilled Vinegar, High Fructose Corn Syrup, Corn Syrup, Salt, Spice, Onion Powder (made from salt), Natural Flavoring (which is artificial by the way)

 

Ingredients of Cheerios:

Whole Grain Oats, Modified Corn Starch, Sugar, Oat Bran, Salt, Calcium Carbonate, Oat Fiber, Tripotassium Phosphate, Corn Starch, Wheat Starch, Vitamin E to preserve freshness.

 

You notice how there is corn and salt in these seemingly unrelated and "diverse" food produce here. Aside from corn, another big ingredient that is used in our food is wheat. So basically, a lot of our food is made from the same ingredients. The vegetables and fruits that come out of the supermarket most likely came from mono-cultures that were loaded with pesticides. I'm not even going to get into what the food in fast food joints are made of; in Taco Bell for example the meat is a lower grade than dog food.

 

Also, life spans continue to increase. The best is women in Japan (86). 20 years ago, their expectancy was only 80. Life expectancy in all OECD countries continues to rise, and I am sure that the access to a wider variety of foods is one factor.

 

Yeah, but this is due mostly to the fact that our sanitation and medical care has greatly advanced.

[SkepticLance]

To Molotov cocktail.

What you say is, of course, correct. However, the availability of the larger variety is still a part of modern life. If you make good use of it, that's great. Some people make poor food choices and do not make good use of the variety.

 

Today, I eat grapes, tomatoes, nuts, broccoli every day, plus whatever local fruits and vegetables are cheap. If I visit the local supermarket or greengrocer, I am faced with an amazing choice of healthy foods, including such things as tropical fruits. If someone continues to eat crap food, that is their choice.

 

Incidentally, that ketchup (tomato sauce to us non Americans) which you disdain, is the richest source of easily assimilated lycopenes. They are the only chemical with an absolutely clear correlation with a reduction in a cancer in humans. High lycopene intake is correlated with a 40% drop in chances of prostate cancer.

[lucaspa]

"Thus, from an energy—and environmental—point of view, it is more efficient for humans to be primary consumers ..." This is a section of text from wiki, in which I find many conflictions with my view of things. First of all, I think it basically states some derived or driving evolutionary process that simply may not exist, or at least not as worded.

 

First, this is a reason that Wiki is only a place to START, not a place to finish your research! Wiki allows people with agendas to write the articles, and the author has an agenda -- which I quoted.

 

Second, there are no "evolutionary processes" in the article. It is discussing carrying capacity of an ecosystem. This does relate to "struggle for existence" because an ecosystem has a finite amount of resources but potentially an infinite number of organisms to use those resources. Not enough resources to go around -- which is what is called the "carrying capacity".

 

So there is struggle between individuals for the scarce resources.

 

The question you have is about primary vs secondary vs tertiary consumers and the energy they use. But think about using data you have from outside Wiki. There are always more herbivores in an ecosystem than carnivores. So yes, a given ecosystem can support more herbivores than carnivores. It's "carrying capacity" for herbivores is greater.

 

Second, our omnivore status plays a huge role not only in our biology but our evolution in memory serves. The idea that humans can get by now being simply vegetarians may be true, but as hunter gatherers or cavemen I simply cant see us taking in enough protein to sustain really, though again in a modern sense is where I find the confliction, in environmental impact that is.

 

Our brains take up a huge amount of energy. The energy density of meat is a lot higher than the energy density of plants. So, turning carnivore to eat meat was a big driver in our evolutionary history. Now, of course, our technology and knowledge has made it possible for use to derive adequate nutrition as herbivores alone.

32. http://www.sciam.com/article.cfm?colID=1&articleID=0007B7DC-6738-1DC9-AF71809EC588EEDF WR Leonard, Food for thought, Scientific American, Dec. 2002. Role of diet in human evolution.

 

I derive that natural selection is really a constant, and in time, organisms in relation to environment either make it or don’t along with adaptation. I think this is where you can find rapid environmental change of enough pressure brings on massive extinction.

 

Yes, natural selection is constantly happening and populations that cannot adapt to changing environments go extinct.

 

The confliction is how this is going to play out for people.

 

Actually, the conflict is more complicated. Because for people, it is not only the survival of the species, but the survival of civilization. H. sapiens could survive in situations where our modern technological civilization won't.

 

So what are your thoughts, do you see a positive future for humans, and how would we reach it really?

 

Define "positive future". What you are doing is moving into the field of ethics and morals and away from science. IOW, what ought to be -- as defined by "positive future". Science can tell you the consequences of various actions, but not whether you ought to do them.

[lucaspa]

I mean just studying what we know of geologic time, or eras such as the Cambrian we can see easily the interconnections of life and the environment. Yet today for the most part such as connection is treated for the most part as non existent, I simply don’t understand.

 

Foodchain, humans can use technology to modify their environment. This is the result of 2 adaptations: the ability to make tools to make tools and the ability to handle abstract concepts and language.

 

This allows humans to 1) escape predation, either macro by large animals or micro by disease and 2) expand our resources faster than our population. Humans have done this by hunting, herding and farming. We still do hunting in terms of fishing, but not so much in terms of land animals. Our ancestors hunted to extinction most of the abundant prey animals: bison, mammoths, Irish elk, etc. We are doing so with a lot of fish and other sea life.

 

But when humans domesticated plants and animals, we were really able to expand our resources by farming and herding. We have been doing that for longer than recorded history and, mostly, have kept ahead of population. In fact, we have been so efficient at it that now less than 10% of our population can provide food for the other 90%, leading to all the other tasks that make up our civilization.

 

May we have to pay someday? Yes. In fact, right now agriculture is beginning to face a crisis because honeybee populations are crashing for unknown reasons. Fully 30% of our food crops depend on honeybees for fertilization. If honeybees go extinct or nearly extinct, then we lose 30% of our food and face our own crisis.

 

So no, humans are not immune from the environment, but our technology does give us a huge buffer against changes in the environment. Such a huge buffer that we can ignore (at least for a while) many effects on the environment.

[SkepticLance]

lucaspa

Honeybee numbers are down. That is a long way from going extinct.

 

And no. We do not depend on honeybees for 30% of our nutrition. The main bulk foods are such things as wheat and corn, which do not need insect pollination. In terms of kilograms or calories, the amount of our foods that need honeybees is closer to 5%.

 

Human history shows a trend away from dependence on natural ecologies. In recent times, there have been several attempts to set up a small population inside a closed environment (the biodome). So far, these attempts have failed. However, each attempt leads to learning more. It is easy to predict that some such attempt will, in the next 100 years, succeed.

 

After that, the next step is to set up a community that does not even need the sun. It will use energy from nuclear fission or fusion. Once that has been proven, humans will be able to set up habitats either underground, or in space, which can survive, and even grow indefinitely.

 

Long term, I predict that there will be habitats (cities?) in space. These will consist of rotating wheels or cylinders, spinning for gravity, with the ability to live independently from the Earth. Once these exist, the destruction or depletion of humanity by natural disaster will become seriously unlikely.

[MolotovCocktail]

The whole point of my first post was that our method of agriculture is not sustainable. Yes our intelligence and technology has enabled us to more efficiently grow lots of food, but our current methods are destroying our environment and wasting lots of resources, many of which are non-renewable.

 

If we want to continue to maintain our standard of living and ensure our survival we have to adopt more sustainable methods of agriculture.

[SkepticLance]

Actually, MC, there is no reason at all to believe that agriculture is not sustainable. Sure, some techniques result in such things as topsoil erosion, and nutrient depletion. However, there are so many methods of preventing or reversing those that we have no reason to accept them as inevitable.

 

Even hydroponics can be used. It has been calculated that the United States alone, if it converted wholesale to hydroponics, could produce enough food to feed the 9 billion that is projected to be the maximum human population.

 

Wonderful soil can be made by mixing ground up rock with compost. We are not exactly short of rock! And this soil is immensely fertile.

 

GM herbicide resistant crops permit no till techniques, with continuous increase in organic composition of the soil. This is already in widespread use with soy beans.

 

The best farming methods, for total sustainability, come from all possible techniques. There are some who talk of organic farming as being sustainable. It is not. This is because it requires high tillage. However, the best methods using organic and conventional agriculture can be.

[MolotovCocktail]

Actually, MC, there is no reason at all to believe that agriculture is not sustainable....

 

I did not say that! What I said:

 

The whole point of my first post was that our method of agriculture is not sustainable.

 

And I have already explained why it our current methods are unsustainable. I do agree that there are many methods out there that are sustainable and will do little damage to the surrounding environment.

 

The current producers of food, agro-business (e.g. Tyson Foods, etc.), are not utilizing any of those methods. That there is the big concern.

[imp]

I did not say that! What I said:

And I have already explained why it our current methods are unsustainable. I do agree that there are many methods out there that are sustainable and will do little damage to the surrounding environment.

The current producers of food, agro-business (e.g. Tyson Foods, etc.), are not utilizing any of those methods. That there is the big concern.

 

Have you considered the fact that bio-engineering of food products and basics has created the ability of producers to become captive-market controllers of parts of the human food supply?

 

For example, if you raise corn, and seek to purchase seed to plant your crop, today's offering of seedstock consists almost entirely of genetically-modified seed which is sterile- that is, you can only get one crop. Next time, you cannot grow more using seed from the previous crop; you must buy MORE of the "scientifically superior" seed. Why is it better? The sellers claim increased insect tolerance, lower pesticide need, larger yield, higher nutritional value, and so on. Monsanto Corp. now introduces an e. coli gene into it's corn seed stock. So, how do you feel about eating product thus related to intestinal waste? Or, will you only sell your crop to an unsuspecting public? imp

[SkepticLance]

To imp.

 

We could be getting into a whole new thread here. That is : how good is GM.

 

I will address only the seed buying issue. You show concern that seed suppliers control a big part of agriculture. Welcome to the post WWII era!

 

That issue has nothing directly to do with GM. Control of seed supply by virtue of the fact that a company sells the best seed is a reality has been with us for the past 60 years. Certain companies, such as Pioneer, Monsanto etc., produce superior seed and offer it on the market. Farmers want that seed and buy it. That happened long before GM came along.

 

Farmers still have the option of buying seed that is capable of producing a harvest, from which they can collect seed, and plant again. The only problem is that they cannot compete with the more productive farmers growing from superior seed.

 

Incidentally, the reason they cannot collect that superior seed and replant is legal - not genetic. Technically, they can replant from seed collected at harvest. It is just illegal. The scientific means to render seed sterile is available. The problem is that when it was about to be introduced, it was vehemently opposed by anti-GM groups, and never got off the ground.

 

The technology was developed by the US government, to avoid the risk of cross-pollination of GM stock to wild stock. In other words, to fix one of the main objections of the anti-GM groups. Only they opposed the fix.

[lucaspa]

lucaspa

Honeybee numbers are down. That is a long way from going extinct.

 

The data I have heard is that the population is crashing and there are fears of extinction. If you have different data, you can of course share it.

 

And no. We do not depend on honeybees for 30% of our nutrition.

 

I said "food crops". That was the information I got from an NPR story. You have changed this to "nutrition".

 

What you are saying is that 30% of our food crops are threatened but only 5% of the kilograms or calories. We both need to check up on the numbers more.

 

Human history shows a trend away from dependence on natural ecologies.

 

I agree. After all, a farmer's field is no longer a "natural" ecology. It is an artificial one made by humans. But can we sustain 6 billion people in biodomes? This gets back to saving the species vs saving civlization. The biodomes you envision can save the species. They can perhaps even sustain a technical but limited civlization. However, they cannot sustain 6 billion people, can they?

 

Long term, I predict that there will be habitats (cities?) in space.

 

Technically, these can be done. Politically? There are a lot of imponderables here, including just how violent the people left out of the habitats and starving on earth become. If the technical civilization crashes before the space habitats can be built, then the technical/manufacturing base to build the habitats won't exist. To build them right now means preserving a small fraction of the human population. Will those inevitably left out allow that?

 

Once these exist, the destruction or depletion of humanity by natural disaster will become seriously unlikely.

 

Destruction becomes unlikely. But "depletion" is still very likely. Is there enough easily obtained metal on the earth to build the habitats, much less the energy to lift the material to orbit?

[lucaspa]

Actually, MC, there is no reason at all to believe that agriculture is not sustainable. Sure, some techniques result in such things as topsoil erosion, and nutrient depletion. However, there are so many methods of preventing or reversing those that we have no reason to accept them as inevitable.

 

You just made MC's point: "The whole point of my first post was that our method of agriculture is not sustainable. Yes our intelligence and technology has enabled us to more efficiently grow lots of food, but our current methods are destroying our environment and wasting lots of resources, many of which are non-renewable. "

 

You are saying that we must change our methods in order to make agriculture sustainable.

 

Skeptic, this is 2 posts in a row where you have not looked at exactly what has been said but responded to something different. First with the switch from "food crops" to percent calories and now trying to say that agriculture can be made sustainable without realizing that such a change means that the original point was valid: with our current methods agriculture is NOT sustainable.

 

For the sake of reasonable discussion, please read the posts more carefully to recognize the points being made. Then you can agree with those points but ADD additional information. It makes the whole process much less confrontational.

 

All your further points on how we can change agriculture to be sustainable and sufficient -- hydroponics, making artificial topsoil, GM herbicide resistant crops -- are very useful additional information, but they are NOT the methods we are using now.

 

Also, eventually, population growth can outstrip ANY technology. It's the old Malthusian equations: resources increase arithmetically but population increases geometrically. So, while I admire your perpetual optimism in technology, the basics of biology say that technology will ultimately be overwhelmed. We need to think about the consumer side -- the number of humans -- instead of only the technology side. If we can't stabilize the population ...

[lucaspa]

Have you considered the fact that bio-engineering of food products and basics has created the ability of producers to become captive-market controllers of parts of the human food supply?

 

Yes. Imp, this gets into issues other than science. GM crops do what Skeptic said. That's the science. How the economics of GM crops work and whether the economics is "good" or "bad" is outside of science.

 

The sellers claim increased insect tolerance, lower pesticide need, larger yield, higher nutritional value, and so on. Monsanto Corp. now introduces an e. coli gene into it's corn seed stock. So, how do you feel about eating product thus related to intestinal waste? Or, will you only sell your crop to an unsuspecting public? imp

 

E. coli are NOT "intestinal waste". Instead, they are bacteria that live in our intestine -- but also live in lots of other places. A single gene from E. coli is not the same as E. coli itself. After all, we have many genes in common with E. coli anyway -- all the genes in basic metabolic pathways! We just have different forms of those genes.

 

You are using an emotional argument here, not a scientific one.

 

For example, if you raise corn, and seek to purchase seed to plant your crop, today's offering of seedstock consists almost entirely of genetically-modified seed which is sterile- that is, you can only get one crop. Next time, you cannot grow more using seed from the previous crop; you must buy MORE of the "scientifically superior" seed. Why is it better?

 

This is a social, economic, ethical issue, not a scientific one. Scientifically, the GM crops have "increased insect tolerance, lower pesticide need, larger yield, higher nutritional value". Now, should those crops also be sterile such that the farmer has to buy new seed each year? You can argue lots of sides to the issue.

 

One side being that it cost Monsanto and other companies huge sums of money to make the GM crops. If they can only sell them once, they can never recoup their costs, much less make a profit. And, if they can't even break even economically, there goes any chance of them doing this again and making better crops.

 

Another side is that we need family farmers in developing nations to raise the food to feed the people there. Such farmers are poor and simply can't afford to buy seeds every year. If the farmers have 1 or 2 bad years, then they go bankrupt and the large companies buy their land. As a society, do we want the means of producing food (and our survival) in the hands of a few large corporations?

 

We, as members of the society, not as scientists, must balance these arguments and consequences and decide what we ought to do with the scientific capability. But that decision is not part of science.

[SkepticLance]

lucaspa said :

 

Also, eventually, population growth can outstrip ANY technology

 

In theory that is correct. However, you might like to check with http://www.un.org/popin which shows the United Nations projections for population growth. It is now expected that the world population will not exceed 9 billion.

 

My optimism extends to believing that humanity can feed 9 billion without causing any kind of global ecological catastrophe.

[lucaspa]

lucaspa said :

 

Also, eventually, population growth can outstrip ANY technology

 

In theory that is correct. However, you might like to check with http://www.un.org/popin which shows the United Nations projections for population growth. It is now expected that the world population will not exceed 9 billion.

 

Again, you are not reading what is written but changing the terms. IOW, you are making strawmen. This is getting annoying.

 

I also said in the post: " We need to think about the consumer side -- the number of humans -- instead of only the technology side. If we can't stabilize the population ..."

 

What you are saying is that the population will stabilize. IOW, you are saying exactly what I did: that the problem must be approached from the consumer side! The addition you are making to my point -- not contradiction -- is that the problem may be solved on the consumer side.

 

My optimism extends to believing that humanity can feed 9 billion without causing any kind of global ecological catastrophe.

 

MC's point was that we can't using existing methods. Pay attention to the bold. There are 2 different claims here:

 

1. Yours: we can sustainably feed 9 billion people by some form of technology/practices.

 

2. MC's: we cannot sustainably feed 9 billion people by current technology/practices.

 

Those are not mutually exclusive and, if fact, you have tacitly agreed to MC's claim by stating that we need to expand the practice of particular technologies. You never agreed that current practices could sustainably feed 9 billion people, but instead pointed out different technologies you believe could do the job.

 

Now, a note on your "data". I found the UN webpage and looked at the assumptions behind the posted table showing a convergence of population to about 9 billion:

 

"To project population until 2050, the United Nations Population Division applies assumptions regarding future trends in fertility, mortality, and migration. Because future trends cannot be known with certainty, a number of projection variants are produced. This note presents the assumptions underlying the derivation of demographic indicators for the period starting in 2005 and ending in 2050. The 2006 Revision includes seven projection variants and three AIDS scenarios. The seven variants are: low, medium, high, constant-fertility, instant-replacement-fertility, constant-mortality, and zero-migration. The World Population Prospects Highlights focus on the medium variant of the 2006 Revision, and results from the first four variants are available on-line and traditionally published in volume I of World Population Prospects (forthcoming). The full set of results for all variants and scenarios are available only on CD-ROM."

 

"Medium-fertility assumptions:

 

Total fertility in all countries is assumed to converge eventually toward a level of 1.85 children per woman. However, not all countries reach this level during the projection period, that is, by 2045-2050. The basic principle of fertility projection is the same for all countries, but projection procedures are slightly different depending on whether countries had a total fertility above or below 1.85 children per woman in 2005-2010."

 

You looked only at the "Medium Variant" table at http://esa.un.org/unpp/index.asp?panel=1 to get your stabilization at 9 billion. And "medium variant" assumes that fertility rates drop.

 

BUT, if you look at all the variants at http://esa.un.org/unpp/p2k0data.asp, a very different picture emerges. If you look at "high variant", then population in 2050 is 10.7 billion and increasing. But even this assumes a drop in fertility.

 

If, instead, you look at the "constant fertility" variant, where fertility rates stay the same as they are today, then population in 2050 is 11.8 billion and rising.

 

So, your optimism is based on some very optimistic assumptions. If we don't make any assumptions about drops in fertility but simply take the data we have and extrapolate it, then we are looking at nearly 12 billion people by 2050 and no stabilization in sight!

[SkepticLance]

lucaspa

 

I get the impression that you are creating an argument where none exists.

 

1. I am not disputing that agricultural practices will or should change. However, I accept that it is going to happen. After all, what farmers do today is not what they did 50 years ago. Agriculture is in a state of constant change. In 50 years, farmers will operate in quite a different way to how they do today. They will be more productive per acre, due to increased efficiencies and better technology.

 

2. Population change. Sure, there are lots of uncertainties in the projections. This is called the error factor. The projection that the world population will reach 9 billion and then start to drop, is an average of many calculations. It is the 'most probable' figure, and will almost certainly be wrong. That is not a paradox. However, the probability of a maximum less than 9 billion is about the same as one more than. The probability of a maximum above, say, 11 billion is very low.

[MolotovCocktail]

lucaspa

 

I get the impression that you are creating an argument where none exists.

 

1. I am not disputing that agricultural practices will or should change. However, I accept that it is going to happen. After all, what farmers do today is not what they did 50 years ago. Agriculture is in a state of constant change. In 50 years, farmers will operate in quite a different way to how they do today. They will be more productive per acre, due to increased efficiencies and better technology.

 

omg, didn't you pay any attention to what he said in the past 4 posts.

 

2. Population change. Sure, there are lots of uncertainties in the projections. This is called the error factor. The projection that the world population will reach 9 billion and then start to drop, is an average of many calculations. It is the 'most probable' figure, and will almost certainly be wrong. That is not a paradox. However, the probability of a maximum less than 9 billion is about the same as one more than. The probability of a maximum above, say, 11 billion is very low.

 

Well, if you actually paid any attention to the last post, you would have caught this:

 

BUT' date=' if you look at all the variants at http://esa.un.org/unpp/p2k0data.asp, a very different picture emerges. [b']If you look at "high variant[/b]", then population in 2050 is 10.7 billion and increasing. But even this assumes a drop in fertility.

 

If, instead, you look at the "constant fertility" variant, where fertility rates stay the same as they are today, then population in 2050 is 11.8 billion and rising.

 

These, SkepticLance, were all the averages of many calculations assuming different scenarios. There is no guarantee that the peak will be 9 billion by 2050 because these calculations are based on the average fertility rate per year. That means that every year or so they have to revise their calculations in order to make up for this.

[SkepticLance]

MC said :

 

These, SkepticLance, were all the averages of many calculations assuming different scenarios. There is no guarantee that the peak will be 9 billion by 2050 because these calculations are based on the average fertility rate per year. That means that every year or so they have to revise their calculations in order to make up for this.

 

The above is just a paraphrase of what I have already said. There is no certainty, and the 9 billion prediction may be wrong.

 

However, it is interesting to note that the predictions have been coming down over the years. A couple of decades back, the UN was estimating more than 12 billion. Then it was 11, then 10, and now 9.

 

The reason for these changes is that globally, human fertility has been dropping. The United Nations demographers now predict that, by 2050, average fertility will be less than 2 children per woman. Thus, the world population will drop. They could be wrong, sure. But they might also be wrong in the direction of over-estimating peak population.

[Cap'n Refsmmat]

lucaspa

 

I get the impression that you are creating an argument where none exists.

 

I get the impression that you're arguing against points that you agree with, without even realizing it.