over population

edpell

Maybe as the population density in these countries decreases the quality and ease of life will increase and at some point they will reach an equilibrium of population (births equal to deaths).

edpell

Let's not get stuck on Alpert he is an extremist. Do we have any more moderate calculations for sustainable number?

mheslep

mheslep

8 billion (= 16 / 2 )

edpell

It seems you are having some feelings about this subject. The question does touch on a core human emotional topic reproduction. I would guess all people have strong feelings about this subject. But I think we can manage our feelings and talk about sustainable number of humans given today's level of technology.

mheslep

Ok, its your thread. Why not start it off with some relatively well established facts or data from respected sources. The video doesn't qualify, even remotely.

Why today's technology, when this issue under almost any circumstance must be dealt with over generations?

edpell

There is an organization called "Population Institute" their website is http://www.populationinstitute.org/p...ustainability/
They say the sustainable population is 5.7 billion.

Then there is the "Optimum Population Trust" at http://www.optimumpopulation.org/opt.optimum.html
They propose numbers from 2.7 billion to 5.1 billion depending on assumptions.

Here is a paper that makes reference to predictions from 0.1 to 2.0 billion. http://www.evfit.com/population_max.htm#note10
With the papers author chiming in at 0.6 billion.

Optimum Human Population Size
Gretchen C. Daily University of California (Berkeley) Anne H. Ehrlich and Paul R. Ehrlich Stanford University (July 1994)
offer "To us it seems reasonable to assume that, until cultures and technology change radically, the optimum number of people to exist simultaneously is [sic km] in the vicinity of 1.5 to 2 billion people."
from http://dieoff.org/page99.htm

mheslep

Erlich was famously wrong to the point of derangement.
Actually Erlich did turn out to be gambler, and lost $10,000
http://en.wikipedia.org/wiki/Simon%E...3Ehrlich_wager

mheslep

I suggest

Resources, Population, Environment: An Oversupply of False Bad News
Julian L. Simon
Science, New Series, Vol. 208, No. 4451. (Jun. 27, 1980), pp. 1431-1437.

lisab

Hmm...he may have had a point there....

http://www.physicsforums.com/showthread.php?t=429726

edpell

OK we do not like Alpert and Erlich. Let's try a different tract setting an upper bound that we can all agree on.

Can we all agree that one human per square meter of Earth's surface area is not sustainable with today's technology? That is 5E14, 500 trillion are not sustainable. Can any one offer a more exact upper bound?

Hells

That's funny. Just the other day I was at an overcrowded beach and felt, darn, how can anyone think we are not overpopulated.

Of course neither of these 2 examples contribute anything to the debate.

What kind of references do you want for Biodiversity crisis, global warming, water scarcity, oil depletion?

Check these BBC articles, especially the graphics which are cited from UNEP.

Biodiversity crisis: http://news.bbc.co.uk/2/hi/science/nature/3667300.stm
Water scarcity: http://news.bbc.co.uk/2/hi/science/nature/2943946.stm
Global warming: http://www.columbia.edu/~jeh1/mailin...mperatures.pdf

Evo

Some questions I'd ask.

Do you know what percent of land on earth is habitable?

Now subtract the arable land from the habitable land, that should give you an idea of the maximum amount of land can be occupied without taking any other limits into consideration. Calculate how much food the arable land can produce, and that should give you an idea of how many people optimally can be fed a healthy diet, again without taking any limits into account.

Now calculate where your people can live, their proximity to food and water, how food and water could be transported to the people that don't have immediate access. Now calculate how that food can be transported to your people and at what cost to the available habitable land space, environment and resources.

This is just scratching the tip of the iceburg. Where are these people going to work? Where is money going to come from? Who is going to provide the healthcare they need and where is the healthcare and who pays for it?

What about nature and the environment? Surely not all habitable land can be taken by humans. Where will the trash go? Where will the animals live?

Have any of you read the UN's paper "Livestock's long shadow"?

http://www.fao.org/docrep/010/a0701e/a0701e00.HTM

mheslep

I agree with both parts of this forecast, regardless of population:

mheslep

Consideration of only the current amount of arable land and per capita food production from it, and naively nothing else, leads to the conclusion that at least the current population of six billion is sustainable, indefinitely.

mheslep

Question: Is India the only large nation left in the world with a fertility rate significantly above the replacement rate of 2.1?

http://www.google.com/publicdata/exp...yMax=71.706936

Evo

It's actually almost 7 billion right now, and the population is increasing, so what is your point?

We can't control weather, arable land is decreasing.

Disregard the pest control, I'm just using this because it shows the FAO charts I was looking for.

continued... See charts.

http://www.agro.basf.com/agr/AP-Inte...d_nature/index