[DesuMaiden]

Yes or no? I don't think so. Daniel Quinn doesn't think so. There is no way we can double our population, and even if did, we can't sustain that population for every long. But I would like to see someone here argue that it is somehow possible to support 15 billion people, even though that would be a crazy assertion.

[Dybbuk]

It would require some kind of technological breakthrough that we can't yet fathom, basically a second (and greater) Green Revolution. It would probably involve farming the sea, since there's no way they're squeezing that much more yield out of land-based crops. GMOs would probably have to play a major role, though GMOs are rightly viewed with a lot of suspicion right now. And maybe some kind of biotech breakthrough which could allow people to survive on fewer calories a day. Altogether I would say it's not quite impossible, but extremely improbable.

[forbin]

Can the world support 15 billion people?

yes we certainly are "going for it " ,

what would it be like ?

very like the Irish Potato Famine , without anywhere else to go .......

http://en.wikipedia.org/wiki/Great_Famine_%28Ireland%29

and the Supa Riche will be all right jack

http://www.bbc.co.uk/news/business-30830296

protected and insulated from the masses

Forbin

[Newfie]

no

[Tanada]

I think the Earth probably could, but it would require wiping out nearly all non human mammal life in order to harvest their food regions for ourselves. Sounds like a super dystopia to me.

[vtsnowedin]

This has been discussed here and elsewhere several times. The answer is that you probably could but would not want to as everybody would be living on porridge three meals a day with some grass fed beef or mutton twice a year. And even if you managed it you would immediately face the problem of the population continuing to grow headed towards thirty billion.
might as well stop now while some wild plants and animals still exist. Here is a bit from one study on the subject:
$this->bbcode_second_pass_quote('', 'H')ow many people can be fed with the cereals allocated to animal feed?

By 2050, 1,573 million tonnes of cereals will be used annually for non-food (FAO, 2006a), of which at least 1.45 million tonnes can be estimated to be used as animal feed. Each tonne of cereal can be modestly estimated to contain 3 million kcal. This means that the yearly use of cereals for non-food use represents 4,350 billion kcal. If we assume that the daily calorie need is 3,000 kcal, this will translate into about 1 million kcal/year needed per person.

From a calorie perspective, the non-food use of cereals is thus enough to cover the calorie need for about 4.35 billion people. It would be more correct to adjust for the energy value of the animal products. If we assume that all non-food use is for food-producing animals, and we assume that 3 kg of cereals are used per kilogram animal product (FAO, 2006b) and each kilogram of animal product contains half the calories as in one kg cereals (roughly 1,500 kcal per kg meat), this means that each kilogram of cereals used for feed will give 500 kcal for human consumption. One tonne cereals used for feed will give 0.5 million kcal, and the total calorie production from feed grains will thus be 787 billion kcal. Subtracting this from the 4,350 billion calorie value of feed cereals gives 3,563 billion calories.

Thus, taking the energy value of the meat produced into consideration, the loss of calories by feeding the cereals to animals instead of using the cereals directly as human food represents the annual calorie need for more than 3.5 billion people.

[onlooker]

This has been discussed at length. Basically, the Green Revolution has played out. We have exploited fossil fuels to create transportation fuel and to extract food from the land at prodigious rates. Now, fresh water is getting scarce, the land is bereft of vitality (dead), fossil fuels are on the downward slope especially as a economically feasible resource. Enormous population and consumer lifestyle is continuing to inflict damage upon the array of ecosystems which maintain a livable environment and same ecosystems are dangerously deteriorating. All this amid a backdrop of ominous global warming which in itself could bring down civilization and even most higher forms of life in the not to distant future. I would say it is actually fortunate for the future of habitability on this planet that we have so populated the planet that a dieoff is now inevitable and could happen soon. A ticking time bomb of environmental catastrophe is ready to go off. So the answer is a resounding NO. Oh and even if we could the way of life would be miserable for most.

[Pops]

Crop production is not falling, perhaps the increase is slowing but the limit isn't calories, even at 15B.

Eliminate beef, dairy, chicken 3x a day and food food calories aren't a problem. Only about 55% of crop production goes to feed Homo directly, 35% is fed to feed animals and 10% to feed machines.

Less than 30% in the US is Homo feed

Likewise pretty much everything else, much less of the 80% that is luxury and much more of the 20% that is basic.

[DesuMaiden]

$this->bbcode_second_pass_quote('onlooker', 'T')his has been discussed at length. Basically, the Green Revolution has played out. We have exploited fossil fuels to create transportation fuel and to extract food from the land at prodigious rates. Now, fresh water is getting scarce, the land is bereft of vitality (dead), fossil fuels are on the downward slope especially as a economically feasible resource. Enormous population and consumer lifestyle is continuing to inflict damage upon the array of ecosystems which maintain a livable environment and same ecosystems are dangerously deteriorating. All this amid a backdrop of ominous global warming which in itself could bring down civilization and even most higher forms of life in the not to distant future. I would say it is actually fortunate for the future of habitability on this planet that we have so populated the planet that a dieoff is now inevitable and could happen soon. A ticking time bomb of environmental catastrophe is ready to go off. So the answer is a resounding NO. Oh and even if we could the way of life would be miserable for most.

[yellowcanoe]

$this->bbcode_second_pass_quote('Pops', '
')Eliminate beef, dairy, chicken 3x a day and food food calories aren't a problem. Only about 55% of crop production goes to feed Homo directly, 35% is fed to feed animals and 10% to feed machines.

[KaiserJeep]

If we halved our population from 7.3B to 3.65B, we are still screwed - we would just suffer twice as long before dying.

If we halved our population again to 1.825B, we are still screwed - we would suffer much longer still.

If we halved our population a third time, that puts us at 912,500,000 - which MIGHT be a survivable number, depending upon how much damage the overshoot population has done so far, that is still reversible to a degree.

125,000,000 is the number we know how to support using 19th century tech without fossil fuels. It's a good lower bound - but populations above that depend a lot on what lifestyle one is willing to settle for, and what tech is still affordable without FF.

This discussion is all academic - until we have a steady state population measured in the hundreds of millions, we are further damaging the planet with species extinctions and human habitat destruction, and resource shortages of all types. This in turn depends upon that die-off being peaceful - that 6+ billion starve and otherwise perish without a destructive struggle or war that further reduces the carrying capacity of a dying planet.

A planet that has in fact been dying for 200+ years, ever since we exceeded that magic 1B population number. Remember that an "event" such as the destruction of the ecosystem due to the overshoot human population may last centuries - as the current mass extinction has, it is accelerating and worsening as the "event" enters it's third century.

[Pops]

$this->bbcode_second_pass_quote('yellowcanoe', '')$this->bbcode_second_pass_quote('Pops', '
')Eliminate beef, dairy, chicken 3x a day and food food calories aren't a problem. Only about 55% of crop production goes to feed Homo directly, 35% is fed to feed animals and 10% to feed machines.

[Tanada]

$this->bbcode_second_pass_quote('KaiserJeep', 'I')f we halved our population from 7.3B to 3.65B, we are still screwed - we would just suffer twice as long before dying.

If we halved our population again to 1.825B, we are still screwed - we would suffer much longer still.

If we halved our population a third time, that puts us at 912,500,000 - which MIGHT be a survivable number, depending upon how much damage the overshoot population has done so far, that is still reversible to a degree.

125,000,000 is the number we know how to support using 19th century tech without fossil fuels. It's a good lower bound - but populations above that depend a lot on what lifestyle one is willing to settle for, and what tech is still affordable without FF.

This discussion is all academic - until we have a steady state population measured in the hundreds of millions, we are further damaging the planet with species extinctions and human habitat destruction, and resource shortages of all types. This in turn depends upon that die-off being peaceful - that 6+ billion starve and otherwise perish without a destructive struggle or war that further reduces the carrying capacity of a dying planet.

A planet that has in fact been dying for 200+ years, ever since we exceeded that magic 1B population number. Remember that an "event" such as the destruction of the ecosystem due to the overshoot human population may last centuries - as the current mass extinction has, it is accelerating and worsening as the "event" enters it's third century.

[vtsnowedin]

$this->bbcode_second_pass_quote('KaiserJeep', 'I')f we halved our population from 7.3B to 3.65B, we are still screwed - we would just suffer twice as long before dying.

If we halved our population again to 1.825B, we are still screwed - we would suffer much longer still.

If we halved our population a third time, that puts us at 912,500,000 - which MIGHT be a survivable number, depending upon how much damage the overshoot population has done so far, that is still reversible to a degree.

125,000,000 is the number we know how to support using 19th century tech without fossil fuels. It's a good lower bound - but populations above that depend a lot on what lifestyle one is willing to settle for, and what tech is still affordable without FF.

This discussion is all academic - until we have a steady state population measured in the hundreds of millions, we are further damaging the planet with species extinctions and human habitat destruction, and resource shortages of all types. This in turn depends upon that die-off being peaceful - that 6+ billion starve and otherwise perish without a destructive struggle or war that further reduces the carrying capacity of a dying planet.

A planet that has in fact been dying for 200+ years, ever since we exceeded that magic 1B population number. Remember that an "event" such as the destruction of the ecosystem due to the overshoot human population may last centuries - as the current mass extinction has, it is accelerating and worsening as the "event" enters it's third century.

[Lore]

Too many factors to account for other than to realize that being on our current path we will have reached our resource limits across many independent life requirements to sustain such a population.

You also just can't throttle back a population and expect the downward spiral to stop after we have used up our water, top soil, affordable and available energy in the midst of a degrading climate. Along with the inevitable disease, famine and conflicts to follow.

In the past people simply pulled up stakes and moved to where they could exploit fresh resources. We've just simply run out of places to go.

[Newfie]

$this->bbcode_second_pass_quote('Lore', 'T')oo many factors to account for other than to realize that being on our current path we will have reached our resource limits across many independent life requirements to sustain such a population.

You also just can't throttle back a population and expect the downward spiral to stop after we have used up our water, top soil, affordable and available energy in the midst of a degrading climate. Along with the inevitable disease, famine and conflicts to follow.

In the past people simply pulled up stakes and moved to where they could exploit fresh resources. We've just simply run out of places to go.

[Tanada]

$this->bbcode_second_pass_quote('Lore', 'T')oo many factors to account for other than to realize that being on our current path we will have reached our resource limits across many independent life requirements to sustain such a population.

You also just can't throttle back a population and expect the downward spiral to stop after we have used up our water, top soil, affordable and available energy in the midst of a degrading climate. Along with the inevitable disease, famine and conflicts to follow.

In the past people simply pulled up stakes and moved to where they could exploit fresh resources. We've just simply run out of places to go.

[DesuMaiden]

$this->bbcode_second_pass_quote('pstarr', 'A')ll the weight in my body is not other species. I am a vegan, and besides when the cows and tofus run out we can just bio-engineer them.