No Government or indeed any political party has a policy on population, yet we continue to bring immigrants here without any particular population goal in mind. To me this is similar to me continuing to purchasse livestock for my property without considering what its carrying capacity is. Any landowner doing this will end up bankrupt or broke.

From time to time various people have given their opinion and this varies from 10 million by Tim Flannery to 50 million by Malcolm Fraser.

OLO seems to have a good cross section of readers and posters, so it will be interesting to see what they think about our best population and why.

I have not settled on a figure myself, but think it important that we discuss the issue. Bearing in mind that over population could well be dissasterous, both economicly and socially.

I was about to start a similar thread myself. Here's what I intended to say.

This is about immigration, not refugees or asylum-seekers.

First a confession. I am an immigrant to Australia. Were I the dictator of Australian immigration I would not have accepted me. For one, I was too old to be a good bet.

This New Zealand article caught my eye.

http://www.stuff.co.nz/stuff/thepress/westcoast/4018185a11.html

The headline is "Migrant benefit 'overstated." The article summarises research conducted by Greg Clydesdale of Massey University on the benefits, to NZ, of migration. Some quotes:

"Current [immigration] policies are also hitting Kiwi families in the pocket and the number of new immigrants should be slashed…"

"Clydesdale said New Zealanders were not being given an accurate assessment of how immigration was affecting the economy and that most previous research on the subject resembled a "wish list", with little hard data showing economic benefits."

What is the situation in Australia?

Is there HARD DATA on the BENEFITS and COSTS of immigration to Australians?

Even if immigration benefits the nation as a whole, it is unlikely that the gains will be uniformly spread.

Who are the WINNERS?

Who are the LOSERS?

I suspect that with immigration, as with everything else, there is a law of diminishing returns. So what is the OPTIMUM LEVEL of immigration for Australia?

What selection criteria should be used for immigration?

I shall mention a few criteria that I think should apply.

--Much greater weight should be given to fluency in English.

--Nobody older than the median age of the country (currently 36) should be accepted. We're an aging society and we need younger rather than older immigrants.

--In the case of married immigrants, extra points should be given if spouses and children over 14 are fluent in English. Points should be deducted for family members who are not fluent.

--Family reunion should be abolished.

--Granting of permanent residence visas should be on the basis of who in the queue has the most points. Time spent in the queue should not be a factor.

Tort.. welcome. Have not seen your posts b4.

Banjo.. I reckon 25 million tops mate. Unless...we can make the desert bloom like the Israelis.

WHY ? simple... infrastructure and WATER. We simply don't have enough.
Melbourne is down to 31% or so.... that's dangerous ! (and this is with consumption DOWN by around 30% on 2004-6 Autumn consumption)

If... we can make the Northern Monsoon areas plus the northern deserts come alive with infrastructure and industry, then I'd accept probably another 10 million up thataway.

FAMILY RE-UNION I'm not against this but I AM against any re-union of polygamous families. ONLY those from the immediate nuclear family can come.

POLYGAMY by defacto relationships must be not only outlawed specifically but punished severely.

IMMIGRATION should be replaced by FERTILITY. Yes, it will take some time, maybe 20 yrs, but it's a worthy goal. Policy can be tweaked to slide gradually from one mode to the other.

Australia will likely have to increase it's population to 30,000,000 to remain in line with global population growth, in order to share the "pain".
As we currently only use 8% of Australia's available water and export lots of our agricultural output, such a number should be feasible. We are resource rich, and have some of the worlds best solar power potential, not to mention wave power and wind.
We could in fact become the worlds most sustainable population at this level.

Rojo,

Are we under any obligation to "share the pain?"

Is there such a thing as a right to immigrate to Australia?

Given that we are fairly sparsely populated even taking into account our aridity and poor soils, why stop at 30 mn? Following your logic surely we are obliged to allow our population to grow until our agricultural and water resources are as stressed as those in China and the Indian Subcontinent.

I'm not advocating anything of the sort – merely carrying your argument to its logical conclusion.

Stephany, yes I beleive we will be obliged by the UN to take in more people, particularly climate change refugees.

Yes, Australia could well support more than 30 million if that's what you want.

My logic is reflective of the fact that the worlds human population is expected to increase 50% by 2050 and there is NO reason that our population cannot do the same. There is also no reason to expect to greatly exceed 30 million. Right about the time our population is around 30-35 million it is forecast that immigration will drop off due to falling birthrates overseas. And with our own low birthrate our population will contract.

Is there a right to migrate here? No. But it's worth a try.

Rojo wrote:

"yes I beleive we will be obliged by the UN to take in more people, particularly climate change refugees"

Maybe, maybe not. Personally I think it's very unlikely but we'll both have to wait and see what transpires.

What if we decline to do what the UN requires, assuming your forecast of UN action proves correct? Many countries do ignore the UN.

Short of an outright threat of really damaging sanctions, or some sort of UN mandated military action, I cannot see any Australian government opening the refugee floodgates. Not if it wanted to survive the next election anyway.

Rojo, Australia simply does not have the water nor the arable land to support 30 million people. In particular, Australia has a real problem with water scarcity, irrespective of your 8% figure. Remember, less than .0008% of the total water on the planet if fit for human usage.

In the case of the planet's driest continent, population growth is pure madness, especially with the looming spectre of climate change. As the CSIRO has outlined, climate change will lead to less rainfall in the southern part of Australia, thus reducing its capacity to sustain a large population even further.

Population growth will only make life worse for those already here. Forgive me for having the misguided impression that Governments were meant to improve the lives of their citizens, not diminish them.

Tortasaurus,
Whenever we talk about demographers, the name of Bob Birrel and Monash Uni in Melbourne comes up. He and his team are very well regarded. The last report by him that I read was a few years ago and, from memory, the main benerficeries of migration were (1) Migrants and (2) Big business and developers. I think he used the term doubtful or probramatical if Australia and Australians received a benefit from migration. I'll stand corrected on this as it is only from memory and there could be a later report. Your NZ report seems to say something similar.

I do not think that report recomended a population figure.

Boaz,
I tend to agree with the 25 million max as not only serious problems with infastructure and water, but also any more would badly affect our standard of living.

I am against family reunion as criteria for immigration. Others can apply and join queue. I also disagree about our fertility rate replacing immigration. There are too many people in the world already and we can easily adjust the numbers we want by immigration.

rojo,
The problem of stats like use only 8% of our water is that it is not where we need itand the cost of getting it is prohibative.

Stephany,
You are right, no one has a right to migrate here. We are generous in allowing others to come here and share in our good fortune. Our forefathers made our good life by their blood, sweat and tears.

Well I guess we could snub the rest of the world and shun the UN. Since our economy relies so heavily on trade any sanctions would be painful.
Please note I didn't say we would all choose 30 million, just that that is what I think it will be. And could be done comfortably.
Will we be invaded by the UN? Not likely, but I would be concerned about how our standard of living would be viewed by our neighbours.

No, I don't think our govt will throw open the doors to Refugees, I think we would be better served getting to "carrying capacity" through skilled immigration, and thus not be expected to accept unreasonable propotions of refugees.

rojo

You repeat the line that unless Australia accepts large numbers of immigrants it will bear the brunt of international sanctions. Are there precedents for this? Japan would be the stand out country not embracing mass immigration, yet I am not aware of any mass international hatred resultant from this. Are you?

Rojo, the water shortages currently faced by our capital cities are indicative of our limited carrying capacity. Based on water scarcity, it is arguable that we have already surpassed our optimum population level.

May I ask why are you so hellbent on inflicting further pain on the Australian population?

For example, you assert that Australia could sustain 30 million "comfortably". Yet, according to the CSIRO, population growth will result in an increase in water scarcity, increased green house gas emissions, a worsening of Australia's trade balance due to more imports and higher consumption of domestic production, overuse of agricultural soils, marine fisheries and domestic supplies of oil and gas, and a decline in urban air quality, river quality and biodiversity.

Is this your idea of "comfortable"?

tortasaurus said: "Who are the LOSERS?"

In short, us.

The average Australian gains nothing from high immigration and population growth. Rather, we face less water per capita, higher property prices, further environmental degradation and pollution, increased consumption of finite natural resources, further pressure on infrastructure and public services, social tension, ethno-cultural division and parallel communities, more urban sprawl and a number of other population related problems.

No wonder why the major political parties discourage any discussion about immigration policy.

rojo

In the EXTREMELY unlikely event of the sort of UN action you envisage the Australian government of the day will have to make some sort of a deal. I regard the probability of anything like this happening as vanishingly small. In fact I think the likelihood is so small that, to be frank, I don’t think it's worth serious discussion.

Absent this sort of "UN pressure," what is the optimum immigration level for Australia and what sort of selection criteria should we apply?

My off the cuff answers are:

Immigration levels should be way below current levels; and

Only YOUNG people with extra-ordinary skills or talents should be admitted.

If I were to put a number to the immigration level I would say 30 – 40,000 per annum of carefully selected immigrants.

I say this while freely admitting that had the sort of immigration regime I am advocating been in place when I applied for immigration to Australia I would never have been admitted.

Pro-immigration propaganda notwithstanding, the NET economic benefits of mass immigration seem to me to be dubious. I suspect the main beneficiaries are what is commonly called the "big end of Town" while most ordinary working Australians either do not benefit or suffer negative consequences

I think rojo's 8% relates to domestic water usage. The other 92% provides our living standards, so if this resource starts to dry up the water will need to be used more efficiently. But before anyone calls for a string of desalination/recycling plants to be set up along the Australian coastline, it is important to note that there are economic constraints to the cost of water. Virtual water is a useful concept for understanding this, though population growth zealots never seem to mention it.

http://www.worldwatercouncil.org/virtual_water/documents/VirtualWater_article_DZDR.pdf

I reckon the ideal population is somewhere akin to Tim Flannery’s figure of 10 million. But we need to be concentrating on the lowest easily achievable figure. And that is in the order of 25 million.

I think rojo’s concerns about pressure to take refugees are very significant. But this should be dealt with almost entirely by addressing the source of the problems through our international aid contributions, with only a very limited intake of the most needy of refugees.

The UN could hardly complain about that, surely. We can very easily espouse the argument that no matter how many refugees we were to allow into Australia, it would only be a drop in the bucket in the world perspective, whereas a boosted international aid effort could help vastly more people.

Of greater concern is the view by our ever-more population-stressed northern neighbours of Australia as an empty resource-rich country with a high quality of life.

But boosting our population is not going to allay any insecurity that we might feel about this. Even if we tripled our population we’d still only have 63 million, compared to more than 100 million on Java alone! We'd still look pretty empty.

We need head as directly towards sustainability as we possibly can, and that means gearing immigration right down and approaching a stable population with priority.
Then, at such a time that we can be sure that we are living within our means, we might recommence population growth. But only if it is within a sustainability paradigm.

David BOAZ, what do you mean; “IMMIGRATION should be replaced by FERTILITY” ?

fester, there are a lot of ifs in a sanction scenario.
if sea levels rise huge numbers of people will be displaced
if agricultural systems fail in different regions
if global population gets to 9 billion
if we ignore the plight of others and shut the doors
if our standard of living is even greater relative to others

It all depends on variables, but I would be concerned if we simply let our water and abundance of land be merely a testament to our standard of living under such conditions.
Population interlinked with climate change is a global issue and will need to be addressed on a global scale. This may or may not be by the UN.

Oligarch, I'm not "hellbent on inflicting pain" via immigration. I'm stating what I think the population will be, and that it can be comfortably achieved.
Very true to say our cities are in trouble, but have a look on a map and you will find many more habitable areas. We have just chosen to congregate in a few.
There is no reason why new cities could not be started in the North and you need not even know they are there. How much contact do you have with Darwin now? It is for most of us a weather statistic. You seem to assume I think we should bring more people to our major cities. That is just dumb.

fester,
Who actually wants to migrate to Japan? They have a population of 127,000,000 in an area less than half the size of NSW. A perfect example of a country where few would feel the need to migrate because it is already highly populated. People only want to move to countries where there is potential to be better off. Lifestyle included.

8% water use refers to all water extracted for use by domestic, industrial and irrigation users. 70% of water extracted is for agricultural irrigation so effectively domestic use is only around 2% of available resource. It's just not all available to the bigger cities. We'll have to build cities where the resources are.

This really is a stupid debate who knows what the future holds?
We globalise our economy, information, money, trade and heaps of other stuff,
yet close our doors to people, doesn't seem to make sense.
Maybe its not the rescoures we have but the way we waste them that we should be debating.
If sea levels rise a couple of metres through global warming, we might no have any choice about how many people we accept, as a major polluter we would be morally obliged to do so.
Alanpoi

Alanpol,
To me, it does not say much for your intellect if you think this subject is stupid.

However, you can start a discussion on any subject you consider of more value just by clicking the box at the top of the page.

“This is a really stupid debate…”

Alanpoi, what on earth do you think is stupid about this discussion? This an extraordinary comment.

I can’t imagine a more important discussion than this one. Working out what our national population should be is one of the core parameters of our economy, society and environment.

“Yet to close our doors to people doesn’t make sense”

Does an open-door policy with no limit on the rate of influx or on the total number of people make sense to you?

Besides, directing ourselves towards a stable population doesn’t have to mean closed borders. I would be happy with net zero immigration, which would still allow for an intake of about 30 000 per annum.

“Maybe it is not the resources but the way we waste them that we should be debating”

We need to debate all of this stuff together. We cannot consider population policy in isolation, just as we cannot consider technology / efficiency / rate-of-consumption arguments in isolation from concerns about an ever-increasing population.

Alanpoi wrote:

"This really is a stupid debate"

So what do you consider a reasonable immigration policy?

Are you arguing for open borders?

alanpoi, your flippant attitude is really quite disturbing, especially when our nation's long-term sustainability is on the line.

Go and spend a week in the slums of India if you want an example of the misery inflicted by unfettered population growth.

Rojo

In a world of over 6 billion I would guess that many would want to live in Japan. But what should open the door for them? Whether the Japanese benefit? Whether the immigrants benefit? A vote? The moral imperative based on the relative mess that the rest of the world is in? Could wealthy nations benefit overpopulation catastrophes better with guidance than sharing their disaster in deference?

Water is quite complicated Rojo, but you can simplify things considerably by classifying it according to its duration of availability or cost of capture. I guess you would be including in you total rainfall things like desert storms and downpours meters from the shore. While all rainfall can be captured in theory, some is cheaper to capture. Even water which is cheap to capture can destroy ecology and industry reliant on natural river flows. Rather than present the raw data, you might show how much of the cheap water is being captured, and how much of that has the perennial availability necessary for domestic consumption. You might also note that people live where they want to, and might not like being shoved about to satisfy some grand economic plan. This might explain why Brisbane is spending three billion dollars on a desalination plant instead of marking every second resident with a yellow spot and forcing them to settle in the far north, and is a great example of how the profits of population growth come at the expense of all.

How much easier would it have been without mass immigration pursued against public approval for the benefit of parasites.

We passed the optimum population - 13,000,000 - for Australia long ago. Too late, now, to think about the problems caused by the big immigrationists of all parties in Canberra. Very small population in that artificial town you will note!

Fester, Japan has had 3544 applications for asylum between 1982 and 2004. Hardly swamped.
It's falling birthrate, and since 2005 population, means japan will face a real necessity to have millions of immigrants over the next fifty years to maintain an adequate workforce, or raise the retirement age to 77. They might just get over their racism.

50% of Australias run-off flows into the gulf of Carpentaria, I don't know what the potential capture and storage would require there but Lake Argyle in WA's North holds 10,750GL and has an average 4000GL inflow.
Sydney, a city of approx 5 million people, uses 635GL/year. So with a conservative approach we could have 10 million up there alone. And climate change models forecast it to get wetter

Rojo

You are only considering the domestic water usage. What about the water required to provide a living standard for the 10 million? Water is needed for industry and to grow food also(It takes about a litre of water per calorie of food on avarage). On the basis of 5 million people using 635 GL per annum and domestic usage representing 9% of total water consumption, 10 million people would need about 14,000 GL per annum, or 3 1/2 times the average annual inflow for Lake Argyle. Your ten million people would be very hungry and thirsty. You haven't been a planner for Australian water supplies have you?

http://www.environment.gov.au/soe/2006/publications/report/inland-waters-1.html

Rojo

“So with a conservative approach we could have 10 million up there alone”

Well you could possibly stick a million up there, but certainly not 10 million. But why on earth would you want to?

The development of northern Australia to any large extent would be highly problematic.

Firstly, if it had been even marginally wet and fertile in basic agricultural terms, it would have been occupied by agricultural Asian peoples many centuries ago. The fact that a hunter-gatherer culture existed there at the time of European contact, with intensive agricultural peoples just to the north, says it all.

Then if Europeans had been able to easily utilise it, they would have, in just the same way that they occupied the agricultural areas of southern Australia.

OK so now we have the ability to implement fandangled water storage and irrigation systems. But this can still only happen on a minor scale, and with real problems with security of supply and basic economics.

Perhaps we could accommodate another five million across the north if we really tried. But again; why?

There is not a lot of difference between your view that 30 – 35 million is a reasonable population for Australia and mine of a maximum 25 million. But I think your reasoning for the extra five or so million seems very flimsy.

You said; “Australia will very likely have to increase it population to 30 000 000 to remain in line with population growth, in order to share the pain.” (9 April)

But you didn’t really explain what this means, when Stephany asked you. You also didn’t respond to my assertion that it would be far better to help refugees at their sources than to accommodate large numbers here. Please see my post of 10 April.

Fester, So what you are saying is that we have no agricultural surpluses and that all irrigated production is required for the amount of people we have now? I think not.
Since we use only 8% of available water then there is obvious scope for expansion. Effectively domestic use is less than 1%(9% of 8%) of water available.


Anyway Sydney for instance uses 635GL/year from an average inflow of 1400GL(1949-1990) however since 1991 the average inflow has been only 697GL/year. Sydney has only 2600GL of storage or 4 years worth if there was no rain at all.
Lake Argyle has 10750GL of storage and an average inflow of 3800GL and it's catchment is not getting dryer. If we double the 635 for 10,000,000 to say 1300GL/year it has 8 years supply without rain and uses only a third of average inflow.

I'm not suggesting we will have 10 million people in Kununurra but it could be done using that water supply as an example. The food can be grown elsewhere.

Ludwig, Stephany seemed to get what I was saying and didn't seem to ask what I meant by sharing the pain, but if you read closely all the answers are in my posts. If you need further help just ask.

30 million because there is no reason not to. Certainly not just because our main cities are short of water, and nonsense about poor soils and being an arid nation limiting such a number.

You didn't address a question to me about your assertion re: external aid. I thought it was your opinion and didn't really disagree. Wouldn't the money be better spent accommodating new Australians and remaining in our economy? A common complaint about immigration is cost to our standard of living yet you would happily give away an amount which could have no other effect than to reduce that standard. If it remains in our economy at least it circulates

Rojo

"I'm not suggesting we will have 10 million people in Kununurra but it could be done using that water supply as an example."

Again I would refer you to this Australian Government site on water availability and use.

http://www.environment.gov.au/soe/2006/publications/report/inland-waters-1.html

Assuming an average population of 19.25 million (a slight overestimate).

http://www.abs.gov.au/Ausstats/abs@.nsf/e8ae5488b598839cca25682000131612/4274f3e53c143e57ca256d46008193a0!OpenDocument

you can estimate the annual water requirement for 10 million people. I calculated this as follows:

Manufacturing 450Gl
Electricity and gas supply 877GL
Water supply, sewerage, drainage 932GL
Household 1133GL
Environmental flows 238GL
Annual Evaporation from Lake Argyle 1400GL

Total Annual water requirement 5030GL

You stated that the annual inflow for Lake Arglye was 4000GL, but what you didn't note was the 1400GL annual evaporation

http://www.connectedwater.gov.au/framework/water_efficiency.html

or the huge range in annual inflows:

http://www.environment.gov.au/water/rivers/nrhp/ord-river/results1.html

From 1984 to 1989 for example, the total inflow was less than 14,000GL. Less 1400GL annual evaporation for the six years, this would leave the 10 million with about 900GL per annum, or less than 20% of their requirement.

The calculation also makes no provision for their food. You state:

"The food can be grown elsewhere."

With much of Australia's food producing areas predicted to get drier, this could pose a problem.

Do you still think that Lake Argyle can support a population of 10 million and give them a decent standard of living? My own calculations suggest that a figure of 1 million is optimistic.

This is an extraordinary column. only one person, in my quick scan of all posts, approached the true problem -- global overpopulation. Oligarch told us to "Go and spend a week in the slums of India if you want an example of the misery inflicted by unfettered population growth." Go to Darfur, Central and South America, China, South East Asia, just about anywhere in Africa and see the same things -- degradation of land, water and air. See the horror that is the lives of about 60% of all humans. See the extinction of animals, birds, plants - the starvation caused by pollution, over fishing, over cropping, the application of poisons to the soil. Australia's population should never have gone above about 8 million to be truly sustainable. the planet's population should never have gone above one thousand million, for the world ecosystems to be sustainable.
Everyone on this forum writes as if population increase is not only inevitable, but not a bad thing. It is an unmitigated disaster! But humans only respond to catastrophe so the impending cataclysm that is climate change, can only be beneficial in the long term for the planet. With a bit of luck enough life will remain to revegetate the planet and perhaps a wiser animal than humans will eventually rise to the top of the 'pyramid'; one that will not overpopulate and foul it's own nest and destroy the very basis of life.

Rojo, your reasoning for 30 million is indeed flimsy; “because there is no reason not to”.

There are enormous reasons not to. But even if there weren’t, why would you want our population to grow any bigger than a level at which we could easily stabilise it? Surely the onus should be the other way round; 30 million only if there is a very good reason for it.

“…nonsense about poor soils and being an arid nation limiting such a number”.

My goodness! I explained in my last post why our northern half (and indeed the whole continent) is so relatively empty; directly because of poor soils and low rainfall.

I’ll extend this one step further; A European cum multicultural society would not have come to exist in Australia if the north had been at all wet and fertile, because it would have been occupied by Asian agricultural peoples centuries ago. Europeans could not have declared Terra Nullius and could not have invaded without a full-on war.

Most of our agriculture is based on the exploitation of poor soils, including the whole wheatbelt. Just look at the state of salinity in our intensive agricultural areas. Salinity is a huge factor in poor soils.

Our agricultural areas are in decline. Oil supply is going to go into decline in the near future with resultant price hikes. This will have a huge effect on our economy and indeed on the economics of harvesting food from areas of poor soils. These factors along with several others make it well and truly time to head towards the lowest level stable population that we can easily achieve, if not take stronger measures to reduce it.

We most definitely don’t want our population to be any bigger than it needs to be.

“Wouldn't the money be better spent accommodating new Australians and remaining in our economy?”

No Rojo. As just explained, we should be heading directly towards population stabilisation, which means that the accommodation of new Australian immigrants is not a good idea, except on a net zero or less basis. It is a much better idea to do our humanitarian bit via international aid projects directed at the problems that generate refugees that it is to bring them here.

It would be good if the money remained in our economy if it was not in conjunction with the support for immigrants. But then we wouldn’t be fulfilling our international humanitarian obligations.

If it remained in the economy in conjunction with immigrant refugees, the increased demand for resources generated by this population increase within our ever-more stressed resource environment would be more significant than the circulation of this money per se. The net effect would be strongly negative.

Immigration is pretty well neutral to our per-capita conventional economics (without even considering the impact on finite and stressed recources). But the support of destitute immigrant refugees is certainly economically negative. And in times of stressed life-support systems on this continent, it would be very strongly negative.

Ybgirp, I can’t speak for anyone else but the reason why I don’t go on about global population to any extent is because it is toooo biiig to deal with. It’s beyond us, just as I feel climate change is.

But we CAN deal with it, and with genuine sustainability, in Australia.

Everyone can see the issues with population at the global level. But there are still some who just don’t get it at the national level. So that’s where our focus must be.

“Everyone on this forum writes as if population increase is not only inevitable, but not a bad thing.”

Really?! Who is saying that it is not a bad thing?

Ybgrip

I am very concerned by population growth and sustainability issues in Australia. While I agree with your heartfelt sentiments, I would point out that there are others with similar compassion and regard for the world who think Australia and the world as capable of sustainably supporting a much larger population. That is why I think it better to look at population growth and sustainability from a logistical perspective rather than a moral one. I know this is somewhat off topic, a discussion of planetary physics in fact, but I like the way this scientist sets the ground rules:

http://www.uwgb.edu/DutchS/pseudosc/flipaxis.htm

"A Note to Visitors

I will respond to questions and comments as time permits, but if you want to take issue with any position expressed here, you first have to answer this question:

What evidence would it take to prove your beliefs wrong?

I simply will not reply to challenges that do not address this question. Refutability is one of the classic determinants of whether a theory can be called scientific. Moreover, I have found it to be a great general-purpose cut-through-the-crap question to determine whether somebody is interested in serious intellectual inquiry or just playing mind games. Note, by the way, that I am assuming the burden of proof here - all you have to do is commit to a criterion for testing. It's easy to criticize science for being "closed-minded". Are you open-minded enough to consider whether your ideas might be wrong?"

Perhaps I should of said pointless instead of stupid.I also said that we don't know what the future holds, if you had of thought about about that instead of the stupid bit, you might have got my point.
Just one scenario.
Imagine sea levels rising, Idian Ocean countries going under, nowhere for these people to go and here we are a vast emty land, how could we say no.
Imagine huge solar power stations 10000sq. kms.in the desert.
Factories next door.
Vertical gardens 50 stories high to produce food.
Water would be recycled.
All this is possible, the technology is there, all we need is men and women of vision willing to go for it and endure the riddicule and unbouded negativism of the naysayers.
We could be the new industrial centre of the world,as we have loads of sunshine going to waste.
It won't be the Australia we have now but so what, I am 62 yrs old and the Australia we have now is nothing like the Australia I grew up in, most of the time it seems like a dream.The Australia (and the world) of the future will be nothing like the one we live in now.
Most of your arguements are about the past and the present, none of you have even attempted to cast your mind into the future except in the terms of today and yesterday.
Some of you have said that that the world can't support any more population, but in the past they said 6 billion and it would fall apart, it hasn't, its in a pretty bad way but it hasn't fallen apart yet.We produce enough food and clothing for every body its just not distrubuted evenly or fairly, mainly through the greed of the West.
I am not advocating an increase in world population just a fairer way of distributing wealth.Oh and by the way if we don't do something about global warming and fast, we will probably have a couple of mega famine's, that might well cut the world population in half in the next 15 to 30 years

alanpoi

As you probably know, there is lobbying for solar thermal power systems with the claimed potential to produce 40 litres of freshwater per kwh of power generation from the waste heat.

http://www.trecers.net/downloads/GCREADER.pdf

If the technology works as claimed then it has a great potential to change things. What concerns me are claims that Australia can support far higher populations when the diminishing water supplies and environmental stresses are all too apparent. Rojo's claim that Lake Argyle could support 10 million and follow up comment that their food could be grown elsewhere is the kind of careless thought that could make Australia's predicament worse.

Ludwig, I wish I shared your sanguine certainties that Australia will be able to deal with population sutstainability -- Howard still isn't convinced climate change is a problem. You ask: Who is saying that it is not a bad thing? No one... my point was that few are saying it is a bad thing... the general consensus appears to be an acceptance of continuing human population increase.
Fester: You say...I think it better to look at population growth and sustainability from a logistical perspective rather than a moral one. The trouble with that is it gives tacit permission for humans to go on breeding. It's the same as offering passengers in a sinking lifeboat a tube of silicone so they can raise the sides a few centimetres. "Oh goody," they will say. "We can let a few more people into our boat."
A most interesting site -- thanks. http://www.uwgb.edu/DutchS/pseudosc/flipaxis.htm
Alanpoi asks us to... Imagine huge solar power stations 10000sq. kms.in the desert. Factories next door.Vertical gardens 50 stories high to produce food.... We could be the new industrial centre of the world,...
Is this the sort of logistics you are advocating, Fester? Would any sane animal want to live in such an environment? there have been many Sci-Fi novels describing such scenarios, and all are horror tales.
What's the solution apart from voluntary extinction? We could support governments that do nothing to combat global warming and climate change in order to hasten human extinction? No - not nice. There's nothing to be done except prepare ourselves and our loved ones for the trials to come. It is too late, even for Australia.

“Ludwig, I wish I shared your sanguine certainties that Australia will be able to deal with population sutstainability”

Ybgirp there are no certainties. I’m not saying that we will be able to deal with it, only that we potentially can. Currently it is not looking good.

“I think it better to look at population growth and sustainability from a logistical perspective rather than a moral one.”

Yes

“The trouble with that is it gives tacit permission for humans to go on breeding.”

Well of course we want to go on breeding, but at a rate that leads to a stable population. I presume you mean that it gives tacit permission to go on increasing our population.

Yes it does. If we were to demand population stabilisation tomorrow, we would have to put a moratorium on immigration and implement immediate measures to see that the birthrate didn’t exceed the death rate. Of course no government is prepared to do that nor are the public prepared to support it. So we will have to accept an increase in our population to some extent.

The important thing is to get ourselves onto the right road towards population stabilisation….and that means knocking immigration back to at least net zero, progressively over a period of about five years, killing off the absurd Costellian baby-buying lump-sum bonus… and accepting our excellent below-replacement birthrate as being a very good thing.

Talk to just about any third world refugee, or a Bangladeshi who's home gets flooded every year, who lives without telephone, internet, electricity, running water, sewerage, a steady income, education for his kids, only the rags on his back and no tenure over his humble dwelling, and my horrible scenario would sound like nirvana, and in fact the middle class in places like Hong Kong, Singapore and much of the world live roughly that way.
In fact that way of living leaves a much smaller footprint than our wasteful way of building Macmansions (on valuable fertile farmland) hours away from our places of work.
The fact is we live an indulgent unsustainable lifestyle, and future generations will probably have to live like the rest of the world (in vertical cities).
What I put forward as one scenario, the more I think about it the more inevitable it seems. Using this self sufficent scenario there doen'st seem to be much of a limit perhaps 100__250 million, thats only 25 medium size cities of about 10 million each, which is only 0.1666666% of the worlds present population a mere soupcon.
Now don't get me wrong I am not advocating that, but is probably closer to mark than anything else I have read here

Fester, You seem to think that just because 9% of water use is domestic that the city requires another 91% to function. Whilst the city will draw on the water resources used in food and electricity they do not have to come from the same source. Just as Sydneys power comes from the outside, like the Hunter valley, so does most of its food. This does not impact on the city supply. We have large agricultural surpluses as it is, with potential to do more in the north where the water is. This is where your theory fails, because 70% of water is used in Agriculture, when nearly all demands are met by dryland production(except rice and some milk, friut and veges). Should demand require it new areas for irrigation will open up in the North. You just have to accept that not everything a city requires comes from it's own water supply.

Can I state clearly that I do NOT advocate a city of 10million in the Ord. Nor do I think it remotely likely.

If Sydney uses 635GL/ year then it is likely that such a city would use approximately 1300GL/year. Your period of 6 years of low inflow suggests 2330GL/year,less your figure of evaporation at 1400GL, leaves us with 900 as you say, which is a 400GL shortfall(from my use figure of 1300GL). At this shortfall a half full Lake Argyle will last over 10 years or a full one 20+.

Throw in some recycling and rainwater tanks if you're still unsure.

“Perhaps I should of said pointless instead of stupid”

Alanpoi, that doesn’t make it any less extraordinary. I say again; I can’t imagine a more important discussion than this one.

Why is it so important? Because we obviously cannot support an ever-growing population with anything like our current level of technological competence, profligacy and stressed basic resource base.

So achieving sustainability and thus living within our means with an intact and strong society is the most important thing. Once we have achieved that or are confident that we are on the right track, we can consider further population growth.

But if we don’t chase the sustainability goal with all our fervour, we are bound to suffer economic and social collapse and a much worse quality of life for the vast majority.

We then won’t be in any sort of state to help the less well-off hundreds of millions around the world.

There are fundamental problems with your enormous ‘technofix’ ideas. The primary purpose should surely be to achieve the elusive genuine sustainability paradigm, and certainly NOT to simply accommodate ever-more people.

The biggest problem with technological advances is that most of them lead directly to the facilitation of a larger population. So instead of improving our future outlook, they are making it more precarious!

Let’s have technological advances as fully as we can implement them. But for goodness sake, let’s have population mitigation along with it.

And yes I agree, let’s pull back on the over-the-top profligacy of McMansions and the like and learn to live comfortably but a tad more frugally.

Rojo, you still have electricity and gas to supply the ten million(877 GL), and what about the environmental flows (238 GL)? I like your water tank option but I dont think that it would get you there. What interests me is the potential of new technology to alter the picture. For example, per capita annual energy consumption is estimated at about 76,000 kWh (http://www.eia.doe.gov/). If solar thermal power works as claimed, then over 3 megalitres of freshwater per capita per annum could be produced as a byproduct.And the water would be produced gradually so you would not require huge storage areas.This is well above consumption estimates considering true water usage, let alone your "The food can be grown elsewhere." calculation. You suggest that an increased population is inevitable due to environmental refugees, but if this technology works here it will work worldwide, with the potential to vastly improve the living standards of billions.

Perhaps we can sustain a greater population. Perhaps we can't.

Leaving aside Rojo's unlikely scenario of us being forced to accept large numbers of "environmental refugees" or whatever, my questions are:

--Should we accept large numbers of immigrants?

--How does it benefit us?

Remember that repeating the mantra "Immigration is good" does not make it so. If you want higher immigration, or even immigration at current levels then:

Give us some HARD FACTS.

Spell out both the costs and benefits.

Tell us who benefits and WHO LOSES.

Let's have some honesty and some critical analysis in this debate.

And let's not get caught up in unlikely scenarios of being forced to take in people.

Stephany, I didn't say we would be "forced" to take in "environmental refugees" it was your interpretation that brought up sanctions and invasion. I see it more as a moral obligation from international groups like the UN as we are emitters of greenhouse gas, and as we are a wealthy, developed nation. We also have the necessary untapped resources.

Is it likely? depends on whether or not cimate change is as great as current dire predictions

Fester, excellent points. Solar would be an absolute win-win situation. The Lakes current hydro electric would provide some of the requirements and also deliver the environmental flows at the same time. The region is home to some of the largest tidal fluctuations in the world, 4 times a day. An awesome potential power source. Fresh water use nil.
The Timor sea region has vast gas fields like the Bayu-Undan gas field which delivers gas to Darwin. WA has 80% of Australias tapped gas reserves. Water use?

No comments on the recycling?

I'm don't understand your contempt for growing the "food elsewhere" as we already produce enough for those extra mouths, let alone the potential production from surrounding areas. Our current cities rely on food from elsewhere why couldn't our hypothetical one.

No I didn't say "inevitable" re: environmental refugees

Rojo

I'm glad you share my hope for solar thermal, and with its proponents claiming to be on track to produce dirty coal competitive energy within twelve months we may not be waiting all that long. Your grow it elsewhere comment concerned me because the water (virtual and otherwise) to support any extra people must come from somewhere. This combined with the fact that much of Australia's already water and environmentally stressed food growing areas are predicted to get drier.

Hopefully solar thermal will become viable before the government flushes half a billion dollars down the clean coal toilet.

fester, your food concerns are valid. However while our systems in southern Australia are stressed through drought at present, they produce far in excess of requirements in all but the severest of droughts.
By all reports the top end will get wetter even as the south gets dryer with climate change and the majority of our water resources are already up there, largely untapped.

The Debnam oppositon in NSW during their election campaign had announced funding assistance to a solar power station in the states NW. Hopefully the Iemma govt backs such a project.

http://bulletin.ninemsn.com.au/article.aspx?id=262081

Would you care to reconsider your view of Australia's food security for the existing population, Rojo? At least wait for a technological breakthrough or the development of a northern food bowl before committing to more people. My understanding of Northern Australia is one of poor soils, seasonal and highly variable rainfall, and a geography unsuited to water storage. It is a climate which many find unpleasant and oppressive.

fester, yes I am well aware of the Murray Darling situation, and I didn't need the PM to tell me there would be no water without significant rain. I notice your link did not say we would run out of food, but that our foodbowl was dry.

In possibly the worst drought in recorded history the nation still produced more than 10 million tonnes of grain. There, as of last week, is currently 13.7 million tonnes of grain in storage.
Half of the nations cattle are in Qld and the NT with Qld's channel country just experiencing some of the biggest flood levels known.
Bore irrigators may have to take up some of the slack and grow more food crops, particularly if vege prices escalate. Whether they can supply enough rice will be an issue.
If you are worried about starving, don't. You might not have the same product choice in the supermarket though.

The majority of the soils in the North would certainly be decribed as poor, but most floodplain country contains suitable soils for productive agriculure and co-incidently they are near rivers too.

fester, yes I am well aware of the Murray Darling situation, and I didn't need the PM to tell me there would be no water without significant rain.
I notice your link did not say we would run out of food, but that our foodbowl was dry.

In possibly the worst drought in recorded history the nation still produced more than 10 million tonnes of grain. There, as of last week, is currently 13.7 million tonnes of grain in storage.
Half of the nations cattle are in Qld and the NT with Qld's channel country just experiencing some of the biggest flood levels known.
Bore irrigators may have to take up some of the slack and grow more food crops, particularly if vege prices escalate. Whether they can supply enough rice will be an issue.
If you are worried about starving, don't. You might not have the same product choice in the supermarket though.

The majority of the soils in the North would certainly be decribed as poor, but most floodplain country contains suitable soils for productive agriculure and co-incidently they are near rivers too.

Rojo

Australia exports food for foreign income. How much food would there be if Australia were to balance the trade deficit with further food exports? Not much I would suggest.

fester, good question. Farmers are constantly reminded that we only constitute 2.7% of GDP and how much better the environment will be without us. How easy it would be to import all our food.

The looming shortage of fresh produce may change these perceptions. That and the fact that even though farming is a small proportion of GDP it has a large share of export income(30% from memory).
I can't see our nation starving itself for extra income, and in reality most of our exports are bulk low priced commodities. As the world population grows and requires more resources they may have no alternative but to buy value added product from Australia instead of us simply providing bulk ie. flour/bread/breakfast cereal instead of wheat. Our unemloyment is low and we will need more people to achieve such an outcome. We could create more income without sending more food.

I dont think we'll starve either, but what help will Australia be to the rest of the world? I disagree with your comment:

"Our unemloyment is low and we will need more people to achieve such an outcome."

Australia has quite a large unutilised workforce. Are they not fit for a purpose? Remember also that a large labour force is currently needed to satisfy the logistical demands of population growth.