zero population growth

antechinus-

Water use is a good point, and a hard nut to crack. Even in the US, we’re seeing serious problems with water rights, farms-vs-golf courses, etc. And we get LOTS of rain.

Conservation here can help, (ban golf???), but it won’t go far enough according to what I’ve read. With enough energy and industry, desalinization will help too. But I don’t know. Perhaps the only real solution will be to cap human use.

In a sense, Australia is a good early test-case for how we can push nature’s limits. With luck, you mates down under will figure out the problem for the rest of us. :wink:

I too find it unlikely that we will run out of food - we are producing more food per person than ever before, and with advances in technology, we will grow even more on less land. The general estimate is that world population will peak at ~9-10 billion, a level which can fed without requiring drastic increases in technology. Now as for other resourses, oil will probabaly get tight, and I don’t know enough at the moment to determine what levels of other raw materials(copper, iron, ect.) will be available in the future without resorting to asteroid mining.

*Originally posted by DreadCthulhu *
I too find it unlikely that we will run out of food.
Running out of food is not the issue. It is maintaining our standard of living. Ecosystems will be destroyed, many food stocks will diminish.

**Now as for other resourses, oil will probabaly get tight, and I don’t know enough at the moment to determine what levels of other raw materials(copper, iron, ect.) will be available in the future without resorting to asteroid mining. **
“Get tight”!?! - oil will ‘run out’ within 200 years.

Dont think of overpopulation being overcrowding. It is consumption of things like energy and water. Population x consumption.

Think of the area of land that is equired to support a person. You do not just take up one square foot. There is all that farmland that produces the agriculture (cotton, grains, meet etc) that you consume.

Countries such as the USA and Australia have much larger ecological footprints than of third world countries. That is, on average in 1997,:
An Australian uses 9.0 hectares.
A US American uses 10.3 hectares.
A Singaporean uses 7.2 hectares.
A pom uses 5.2 hectares.
A Bangledeshi uses 0.5 hectares.

Obviously reducing consumption and population are two ways of reducing a countries overall ecological footprint.

If the U.S. can support 300 million, why can’t Australia support 50 million?

The first settlers in California starved to death. Now there are 70 million people there.

By the way, vegetarians require far less land than omnivores: 1/4 acre vs 3 acres for an omnivore. I know we “civilized” people use more land for our luxuries. But you can certainly see the advantage of using 1/12 the required land, especially when food is one of the major arguments about overpopulation.

Something to think about. Look at india’s ecological footprint. Even though they have the second largest population, they are tied with ethiopia and pakistan for the smallest ecological footprint. This might not have anything to do with them being mostly vegetarian. It’s most likely more due to the modest lifestyle and the meagre .5 hectare/person capacity of the country. But surely them being mostly vegetarian helps them a bit.

I’d also like to point out (again) that overpopulation levels out over time. As each country enters the modern world, it goes through a period of imbalance. Improved health care and higher food yealds mean less infant mortality and a larger elderly populace. Even the USA went through it. The whole world (according to this website) is only in defecit 0.7 hectares/person as of 1997. This I believe we can reason out to be caused by the majority of the population living in countries that are in the process of modernizing. (China has the 2nd largest overall footprint. India has the 4th. USA and Russia are of course 1st and 3rd. And India + China is still a smaller footprint than USA.) As the countries eventually become more modern, the populations’ will diminish naturally. In about 100 to 200 years the whole world will be levelled out. I’m not worried at all. We will probably still have to tighten the belt, but not too much. And technology will certainly help maintain the status of living. IF we can only break that energy barrier. (Get us off fossil fuels.)

There is debate over whether Australia can sustainably support our current 20 million. If our land management practices are improved (we can learn from the Israelis) then we may be able to.

At a pinch, with greatly improved efficiencies and reduced standard of living, we may be able to support 25 million sustainably. 50 million would not be sustainable.

As I said Australia is an arid country.

Not only the initial immigrants, but the fact that many of them tend to have more children.

I read something recently that predicted the large increase in U.S. population, while at the same time a major decrease for the Europeans. Contrary to general opinion they therefore predicted continuing prosperity for the U.S. and a decline for Europe. This is why there is a shift towards the Pacific Basin, in world power.

I think it was the Economist that had that article on increasing US population/decreasing European population. I can’t seem to find that article at the moment, but basically it said US population would pass up Europe’s by 2030 or so. As for power shifting to Asia, China is already the second largest economy and growing, followed by Japan, and India will likely catchup soon enough. In the next century, China and India will be much more influentional.

There is scant lack of opinion here - if we are not careful this thread might end up being shifted to GQ. Help Sam Stone, we need an opinion.

The first fleet to Australia nearly all starved to death because they could not grow crops.

The US has deep fertile soils over much of the country and fairly good rainfall. Australia has only a few patches of fertile soil and low rainfall. Water is the big limiting factor.

No.

According to Popultaion Reference Bureau Bangladesh’s Total Fertility Rate (avg no. of
children born to a woman during her lifetime) is 3.3 and Population Change 2002-2050 (projected %) is 54%.

3.3 is not barely above replacement.

REFERENCE

Natural population decrease (not including net immigration) seems to be linked to life expectancy and literacy.

The goal of trying to reach ZPG is a noble one if we wish to sustain a good standard of living.

I would say that that is exactly the wrong way round,

and rephrase it…
The goal of trying to reach a good standard of living is a noble one if we wish to acheive ZPG.

To have a good standard of living everywhere, not just in the west.
The main difficulties are energy management and water management.
There is galore of water on this planet, it just needs energy to desalinate it.
This reduces the problem to energy alone.
If we utilised a much higher proportion of the incident sunlight that falls upon this world, and practiced enegy conservation, the entire present population of the world could live at western standards of comfort, and population would regulate itself.
If we were careful to avoidaltering the effective albedo of the planet we could even avoid global warming.

Personally I would want to gather extra sunlight using orbital solar collectors, but the extra energy cannot easily be used on Earth without melting Greenland’s ice, so that is not recommended.

I agree that in order to reach ZPG due to natural population expansion a good standard of living must come first (social security, long life expectancy and good education).

However, in order for countries that have already reached natural ZPG to maintain a high standard of living (also include sustaining ecosystems and agricultural areas) then net immigration must be managed to maintain ZPG.

The ones who don’t advocate ZPG are advocating population growth. There’s no third possibility. To them I ask the following:

Do you think population growth will help or hurt our quality of life, with regard to land prices, environmental conditions, congestion, or traffic? Why?

Actually, it is, when you compare it against birth rates of 6 or 7, which it was in the recent past, and when you factor in the high childhood mortality rates.

Furthermore, the birth rate in Bangladesh is expected to continue to fall to 2.2 in the next few years. And the reason isn’t increased wealth, but access to contraceptives and increased knowledge of family planning. At least, according to UNESCO.

From: THE POPULATION IMPLOSION – NY Times Page One Special Report, 7/10/98.

"Driven largely by prosperity and freedom, millions of women throughout the developed world are having fewer children than ever before. They stay in school longer, put more emphasis on work and marry later. As a result, birth rates are now in a rapid, sustained decline.

What was once regarded universally as a cherished goal – incredibly low birth rates – has suddenly become a cause for alarm. With life expectancy rising at the same time that fertility drops, most developed countries may soon find themselves with lopsided societies that will be nearly impossible to sustain: a large number of elderly and not enough young people working to support them … There is no longer a single country in Europe where people are having enough children to replace themselves when they die. Italy recently became the first nation in history where there are more people over the age of 60 than there are under the age of 20. This year Germany, Greece and Spain will probably all cross the same eerie divide … The effects of the shift will resonate far beyond Europe. Last year Japan’s fertility rate – the number of children born to the average woman in a lifetime – fell to 1.39, the lowest level it has ever reached. In the United States, where a large pool of new immigrants helps keep the birth rate higher than in any other prosperous country, the figure is still slightly below an average of 2.1 children per woman – the magic number needed to keep the population from starting to shrink.

Even in the developing world, the pace of growth has slowed almost everywhere. Since 1965, according to United Nations population data, the birth rate in the Third World has been cut in half – from 6 children per woman to 3. In the last decade alone, for example, the figure in Bangladesh has fallen from 6.2 children per woman to 3.4. That’s a bigger drop than in the previous two centuries … “What is happening now has simply never happened before in the history of the world,” said Nicholas Eberstadt, a demographer based at the American Enterprise Institute in Washington. “This is terra incognita. If these trends continue, in a generation or two there may be countries where most people’s only blood relatives will be their parents.” … There used to be many more young people than old people in the world. Right now there are roughly equal numbers. But by 2050 there will be nearly twice as many old people as young people … If there is a ground zero in the epidemic of low fertility it would have to be in the northern Italian city of Bologna, where women give birth to an average of fewer than one child (in 1997, the number was 0.8).

The city has more highly educated women than any other in the country. Incomes average more than $16,500 a year. Produce is rich and cheap, food is wonderful and living is generally easy. The local population has dropped steadily for two decades, but 1,500 people turn 75 every year… In 20 years, at present birth rates, for every child under the age of 5 in Bologna there will be 25 people over the age of 50 – and 10 older than 80… How did Italy, a largely Roman Catholic country that has always been seen as the stereotypical land of big, close-knit families, became the place with the world’s lowest level of fertility? “Prosperity has strangled us,” said Dr. Pierpaolo Donati, professor of sociology at the University of Bologna…"

autz and others,

See also The World Turns Gray.

If you can find the original US News and World Report Article, it has some interesting graphs. One that stood out - by roughly 2050 (given current population trends) there will be more old people than young people alive in the world. If (or when) this occurs it will be the first time in human history that the percentage of old people (those 60+ years or older) will be greater than the percentage of young people (those less than 15 years of age).

Also, as has been gone over many times on this board, according to the U.N. World Population survey, if their ‘low’ estimate for population trends comes to pass, the world population will begin to decline after 2050, and will drop to 3.6 billion by 2100. That has huge ramifications for the world economy. The median, or most likely estimate has the Earth’s population stabilizing at somewhere between 9-10 billion. But I believe that number will be adjusted downwards again, because the trend towards low birthrate is still increasing.

Well, we need low birthrates by 2100 because life expectancy, and I would suggest duration of fertility, will be an indeterminate amount longer by that time.
This pattern will continue until the population is nearly all old people… but not necessarily decrepit by any means.

I agree that the population will age, and stay aged permanently because of longevity and low birth rates.

There is a big implication here - very soon now (like, within 10 years), there is going to be a big demographic crunch affecting Social Security, medicaid, and other retirement programs. As the baby boom retires, we’re in big trouble because we aren’t replacing the retiring workforce with younger workers with which to support them.

Back when the retirement age was first set at 65, life expectancy was something like 72-75. That means society only had to pay for retired workers for a fairly short period of time before they died.

But within 10-20 years I wouldn’t be surprised to see the life expectancy of people who are at retirement age to be closer to 85-90. Allowing people to retire and collect social security for 20-25 years while there are only 2 workers paying taxes to sustain him or her is clearly not feasible.

So I expect to see pressure in a few years to raise the retirement age to 70. But since it’s the baby boomers that will be affected, this is going to be almost impossible to do. The only other alternative will be massive tax increases on poorer, younger people in the workforce, to pay for benefits that go to older, wealthier people. That’s going to create a lot of trouble in society.

At some stage there will have to be a high proportion of elderly people as we move from an expanding population towards a stable one.
Once we reach ZPG, then the population frequency distribution stabilises as well. We should not get used to relying on a larger number of young people caused by an expanding population.

What I was getting at in the previous post was that - we have to face that sooner or later the population will reach a ‘natural age distibution’. So it may as well be sooner, just putting the ‘problem’ off will make it worse in the long run.

The economy is addicted to a growing population. We should go cold turkey, deal with an aged population for a while, until we settle into a stable state.

That NY Times article is alarmist - the trend to lower birth rates should be reported as good news, but good news never makes a good story does it. The fact is that the world population still is increasing exponentially and will continue to while replacement rates are above 2. Even if the rate drops below 2 the population will continue to increase for a while.

sam stone3.3 is not barely above replacement, even if you compare it with 6 or with 600.