Ludvig,
I wouldn't want down play population as a factor or argue against holistic views on problems, what I'm actually asking is more holistic thinking is needed right across the board, in addition to the points your making, which are well known to most people, and to me since the 60s. And remember too, in a word-limited essay one cannot cover everything.

If you think I'm pandering to untrammelled growth, then I suggest that you're missing my point. What I am saying is that economic development is a lot more subtle than the simple anti-growth advocates make it out to be, and that there are many practical realities about growth that simply won't jump to our wishes, even though most of us hope they would. These difficulties have to be part of a holistic view.

One of the chief practical realities is that grand Utopian-versions of visions to remake the world, and single-issue views of the world-and the zero-population movement in my view one of them - are generally worse than the imperfect situation that precedes them, because they often ignore local requirements and special needs. This should also be part of the holistic view.

This problem of Utopian-grand visions, can't be simply dismissed by mockery or hand waving. Treading carefully with bottom up locally proven ways to reform the world is a good strategy. The practically achievable needs to be assessed as well as the desirable. A genuine holistic view has to take in the complications of both industrial ecology and natural ecology, as they are both part on the overall system.

I don't see population growth in prosperous counties as the most important problem though, and that's where this thread started. I think the biggest challenge is to accellerate poor countries through the demographic transition, and see elimination of poverty is a necessary preliminary to achieving a stable global population and a human welfare positive. If India and Africa become richer quicker the population issue will become resolved quicker.

Ludwig clearly implied that an increase in water use or farming productivity would lead to an increase in Australia's population and this has no basis in fact. Indeed, most of the productivity increase has taken place in areas of low population growth. And there is no mechanism within the department of immigration that ties annual intake quotas with agricultural productivity or water availability.

So can we get back to this excellent topic without the blog stalking?

Are we agreed that any process that enables the exchange of water in the biosphere is more ecologically contributive than a process that does not?

Are we agreed that a process that can increase the frequency of water cycling through the biosphere is more ecologiclly contributive than one that decreases the frequency.

For if these two assumptions are valid then the worst place to have a city is at a river mouth because this will increase runoff and deliver it to a point, the river mouth, where its potential contribution is minimal.

Conversely, the best location for a city would be at the top of a catchment where the urban runoff would be delivered to a point where the opportunities to maximise the frequency of water cycling through the biosphere would be greatest.

It would also follow that the best location for water storage would be as far up the catchment as possible as that would enable the multiple use of water so it delivers an environmental flow service at the same time as it is being delivered to a downstream user. In effect, the irrigation water delivers the environmental flow as well.

Any thoughts?

Dhaw,

There is not enough OIL to achieve the immigration led growth UTOPIA that you and the big Mac Banks wish for.

What we the citizens will be left with in 10 years is angry mobs killing each other for tunnel funnelled petrol while you and your special interests are using your quick profits to build fortifications to protect your investments.

Now if the majority can see Peak Oil in its true eventuality then Type A personality special interests will be left high and dry by majority rule and we WILL get a zero population growth for Australia after a slower growth to about 23 million. And note, no more people in Sydney or SEQ till services are up to public expectations. That would kill immigration right there. This is as it should be.

Take a reality pill and don't assume you can ride your fellow citizens like a donkey.

In the meantime, there is only one way to manage water. Bring more RAIN in from precipitation bands over the coasts. You do this by
* patchwork flooding Lake Eyre to lower SA regional temperatures so Sthn coastal rain bands flow more regularly into the Eastern states and not into the Tasman sea to be wasted.
* by creating 100,000 engineered wetlands (EWBs) all over Australia. EWBs retain desert heat energy and moisture at strategic saddle points. This Thermodynamic heat energy is necessary to permanently green Australia. This heat currently reaches the Sth pole as pollution via atmospheric and oceanic circulations to the roaring forties and is a major contributor to ice cap melting.

Proposed water management stategies, green water or otherwise, with existing poor land management practices (particularly in Victoria) is like shuffling deck chairs on Titanic.

Further, intense scrutiny of the dynamics of this catastrophe are making many climate (nee biologist) scientists blind to the important thermodynamic constraints that are placed on regional climate by poor land management in Australia, Sth Africa and Sth America.

Surely this discussion must be from a global perspective.
Discussion about population growth in Australia seems irrelevant against our potential envelopment by the environmental damage and unrest stemming from scarce resources, on a global scale.
I think one approach to alleviate this potential envelopment is described by David Tribe in ‘More crops per drop’.

So sticking to the topic, Preseus, I have been suggesting that Sydney should expand by developing west of the mountains, facilitated by 1st world road and rail links. Orange would then be in comparable proximity to Sydney as Newcastle and Wollongong.
This would be in line with your suggestion that cities should be built in the upper catchments to maximize water recycling and environmental flows.
This is one more reason to halt development of the Sydney basin.

Very good David. Thankyou

I still have some issues with this and I would love to continue this debate, but while it was on-subject to raise it I guess it is a bit far off-subject to continue, in the absence of specific reference to water issues.

Can I ask you for your thoughts on my other two concerns (1 and 3) of my post of 9/2.

Geoff, I think all bets are off once a city gets to 3 or 4 million because, like it or not, it is just there. Sydney is already past the point where problems compound in complexity and cost. Every person in Sydney now has very strong self interest motives to encourage people to go somewhere else. To smaller cities where new approaches can be trialed on greenfield sites.

They can do a lot to help themselves by installing decent size water tanks etc to reduce the call on up catchment blue water. But the big problem is finding space for the collection of grey and storm water for re-sale to farming and other uses. I suspect that given the distances and heights to be pumped over, Sydney waste water would need to be "souped up" with additional fertilisers etc to add additional value to the product to justify the higher pumping expense. And that would invite the question, what other wastes are being disposed of at a cost, which could be added to water to enhance it's value to another user?

Don't know that one.