Cities are just one aspect of a civilisation. Societies across the world collapsed after a massive volcanic eruption in Indonesia circa 630 AD heralded the well-named dark ages. Access to cheap energy which with today's technology is principally carbon based (of which fossil fuels are only part, refer the work of Thomas Gold The Deep Hot Biosphere) - but which in future will be nuclear, hydrogen or electromagnetic based, is our only defence against the gargantuan forces of nature. As Lang Hancock observed, 'eco-nuts - let them freeze in the dark'. When are we going to get real and stop the nonsense of pretending we can change the climate by restricting production of a trace gas in the atmosphere, life enhancing carbon dioxide? When are we going to get rid of complex tax laws which inhibit creativity and innovation?

John McRobert

Interesting article Edward. But I feel that something major is missing.

You talk of overstretched infrastructure, but you haven’t even alluded to continuous population growth as being in any way a factor.

Surely it is, in at least some ancient cities, and very much so in today’s declining metropolises.

It is rapid population growth that stresses infrastructure. This is surely a critical point.

While the climate may change, energy may become more expensive and hence the whole economic regime may change, it can only be made worse by heaping more and more pressure on the whole infrastructure and services system of a city via continuing population growth.

If populations stopped growing in stressed cities, then surely there would be much more available funding and human energy to be put into the repair and upgrade of overstressed infrastructure and services, rather than into building more and more new I & S for the ever-growing population.

And as the climate changes and energy becomes harder to obtain or more expensive, smaller populations will be easier to sustain, whereas larger population centres would be more inclined to fracture, suffer in-fighting, breakdown of the rule of law and general collapse of society.

Today New Orleans, tomorrow the Netherlands!

The trouble with the whole "densification" movement is that its proponentsa are not talking about dismantling the suburbs and moving people to a denser centre. Densification is just being used as an excuse for continued population growth. But the main reason cities need "infrastructure" is to bring in resources (i.e. food) and to remove wastes (e.g. sewerage). Since only a finite amount of food can be grown per hectare, as a city's population increases the area of land that must be devoted to growing food for it increases and the energy and infrastructure requried to transport that food to the city (and flush away the wastes) also increases. So ultimately, densification does not make a city more sustainable. In fact, it makes it less so since the large a city the more energy per capita its inhabitants require (see http://www.energybulletin.net/stories/2012-07-23/spatial-emergy-concentration-and-city-living )

The primary constrain on survival of a city is its food supply:

http://www.onlineopinion.com.au/view.asp?article=12863

Today New Orleans, tomorrow Cairns!

It is a wonderful sunny winter's day here in north Queensland.... but this regional city is precariously built on very low-lying land and is prone to total wideout by a cyclone-generated storm surge or a relatively small sea-level rise.

John McRobert has it correct about taxation. We've taxed labour and capital to a standstill because tax regimes repetitively favour the creation of enormous real estate bubbles.

Mason Gaffney has provided deep historical insight into how strong political leaders used land value taxation (LVT) to regenerate US cities - http://thedepression.org.au/?p=11491 . The facts can't be disputed, but where are our political leaders and town planners on LVT and urban renewal?

"Climate change plays a part but is not the sole culprit."

Do we really have to keep listing all the meteorological disasters that took place before it became fashionable to bleat about 'climate change'? Most of them, incidentally, involving much greater loss of life, largely because the economic resources weren't there to protect people.

A good place to start is here: http://www.ranker.com/list/the-worst-droughts-and-famines-in-history/drake-bird

Of course, if by 'climate change' you mean 'natural variation', then I agree completely. It's a terrible thing, except when it's not -- e.g. greening the Sahara. But what are you suggesting we do about it?

Sorry Prof Blakely but you have wildly over-stretched the analogy. You may or may not blame climate change for an increase in the number of extreme events - and this point is still hotly debated despite what the IPCC view might be. But the collapse of the modern US urban areas he mentioned had much more to do with government failure, such as permitting people to build in low lying areas when not enough money has been spent maintaining levees.

Much the same trade off occurs here with building codes. Never mind whether we will get more storms in Northern Queensland, have the building codes been properly designed and enforced? That's what matters. The article is sloppy thinking.

Curmudgeon,

You are so spot on.

'Never mind whether we will get more storms in Northern Queensland, have the building codes been properly designed and enforced?'

Here is a fact that few would know.

Qld Building codes only require houses to be built to survive a Catagory 4 cyclone.

ie Sustained winds of 86-107 kt (160-200 km/h)

Gusts of 122-151 kt (225-279 km/h)

Here are facts few recall and noone publishes,

Cyclone Yasi winds destroyed very few buildings ($ 0 .8 Bil, Infrustructure and bldgs)less than Cyclone Larry, ($0.5 bil Structures in Innisfail). Official examination of damage indicated winds were variable with most damage caused by cat 3 winds and only some (isolated) areas suffering Cat 4 winds.

At the time all the media reported and 'climate extremists' (incl the BOM) claimed Yasi was a Cat 5, an 'extreme climate event' and only one of a forecast many cyclones to hit Nth Qld last year. There were only four to cross the Qld Coast that year and two were little more than rain depressions as they crossed.

This year the 'climate extremists' including the BOM, predicted numerous and more intense cyclones. There were none.

Again the weather is failing the alarmist predictions... and no-one in the media comments.

Why is that?

What a dishonest article!

No mention of the real problem with New Orleans. That it was built on low land, which had settled to much lower, & well under sea level. That the dikes to protect this below sea level city were definitely inadequate, or that the pumps required to pump normal rain water out of the place were built below even the low ground level, & quickly flooded.

The whole place was a disaster waiting to happen, & the city administration too dumb to do anything about it. Surely even an academic can see that there is a reason that there were 15000 vacant housing units in the city centre. Obviously no one wanted to live in this city planners idea of utopia.

No amount of long winded dishonest dissertation is going to change this. What we need is some planners who design what people want, & then cater to that model.

There is no connection with this catastrophe, & the point the professor is trying to make. Further he makes no even moderate argument to support the stacks on the mill city of his desire.

These town planing people all suffer from the same idea. Jam everyone into the minimum space, suburbs are bad.

Well sorry Edward, from what I see most of our troubles today are from overcrowding, not suburban sprawl.

Here's a new idea. If suburbs can't save cities, abandon the cities. People don't want to live there anyway. Demolish the garbage, & make the areas market gardens, reduce the transport requirement, & every one can live happily ever after in the suburbs.

Today New Orleans, tomorrow Cairns!

It is a wonderful sunny winter's day here in north Queensland.... but this regional city is precariously built on very low-lying land and is prone to total WIPEOUT by a cyclone-generated storm surge or a relatively small sea-level rise.

[reposted. Now it might actually make sense!!]