I doubt we're reaching the apex of magacities and I don't think we'll see the sudden collapse of one either. Unless personal transportation is so improved as to make travel from rural areas to the city cheap, fast, and effortless, more people will move to cities. Baghdad is a good example of how resilient large cities can be. Since the early 90's the critical infrastructure (water treatment, electricity, etc) has been in shambles and still is today. Yet even with sanctions, invasion, ethnic cleansing, and horrific daily violence, millions of people still live there. How much worse could it get than that? Nothing even remotely close to that will ever happen in an american city, so I think we'll be fine. As for the popular survivalist scenario of a mass exocus of desperate citydwellers ravaging the countryside for resources I say, keep dreaming.

You make a good point. We, the allies, bombed Berlin to rubble and then two Russian armies set about redecorating the place while the Third Reich had its last gasp and old men and children set about to make the remodeling job as messy as possible. Then it was split in two. But Berlin remained a great city.

It is late, early, and I can't come up with any city of any size that was abandoned in the last few hundred years.

I go down a list of cities with major issues and disastrous conditions and I can't think of one where people just gave up.

Berlin, Hamburg, Dresden, Hiroshima, Nagasaki, Tokyo in WW2. Sarajevo during the Balkans conflict wasn't abandoned even as it was blasted, tortured, and converted to an open air shooting gallery. Baghdad, Fallujah in more recent times.

Cities are remarkably resilient. City dwellers are quick to adapt and quite tenacious.

I suppose that there is some degree of damage that would force a city to be abandoned. Soviet war planners had, according to one account, a plan that included 24 nuclear warheads, in sizes up to twenty megatons, going off over Washington DC. Hard to imagine rebuilding but I'm not entirely sure about it.

The Texas power grid is solid. We only have a problem when an electrical substation went down and when severe weather knocks out the power lines.


That was because the power lines went down. It has nothing to do with the grid.

Jeanette Isabelle

Icing on power lines was only one of the issues during that time. Among the problems, the cold actually shut down power plants themselves. And a huge increase in residential natural gas use caused the utilities to shut down many natural gas fired power plants to divert natural gas to their residential customers. (I get the impression that the hassle and danger of turning on millions of pilot lights for residential natural gas customers was a bigger concern than letting the gas fired power plants shut down.) This article describes that episode and how the blackouts happened. It says that 50 Texas power plants dropped off the grid. The wholesale price of electricity spiked from $70 MW/hr to over $3,000.

The article also mentions the deregulated Texas power market. The energy companies aren't required to build enough power plants, or even any power plants, if they can get their power from someone else. That's why the shutdown of gas-fired plants in the next few years will happen in Texas, as I mentioned in my previous post.

As long as there is just enough power to meet demand, then prices will remain too low for these Texas energy companies to have a financial incentive to make those expensive upgrades to those gas fired plants. Therefore, any sudden loss of capacity, like that winter episode, or a sudden spike in demand will lead to blackouts.

Let's not forget Grozny. The Russians leveled that city more than once, but it is still inhabited.

The only city I can think of is Pripyat, in the radiation exclusion zone around Chernobyl.

There must be any number of cities in the Russian interior that have declined considerably since Soviet times. Of course, none of these are megacities, which is the OP's interest.

Oh, certainly not a megacity, but Ajdabiya in Libya essentially emptied out completely due to the fighting there. Of course, once the dust settles, residents will likely return, I presume.

However, certain events in recent memory make me wonder how soon before we see a major city actually abondoned for one reason or another. If things had gone a bit differently, what might have happened in the short term or longer term with certain recent events. Events like Katrina and New Orleans, the recent Mississippi River flooding, Deepwater Horizon and the Gulf ecosystem, the surprise massive earthquake under Chrischurch, NZ, the earthquake, tsunami, and nuclear situation in Japan, etc.

Especially in Japan, what if the earthquake and tsunami had occurred closer to Tokyo? Or what if the prevailing winds from Fukushima Daiichi had blown radioactive particles southwest towards Tokyo most of the time instead of straight out to sea? This situation in particular really concerned me considering the size and importance of a megacity like Tokyo.

This had nothing to do with the grid. Grid-related issues are technical. This was not technical. The major problem is the coal-burning power companies did not prepare. The second problem was only minor and it may not have made a difference. Oncor did not have all of the information they needed.


Jeanette Isabelle

Quite right. What I described in my last post wasn't a grid problem, but the circumstances of an event that illustrate a weakness of the Texas grid, which is what I was talking about in the post before that one. I got too wrapped up in the details.

The bottom line is that the problem for the Texas grid was that it couldn't compensate for the loss of generating capacity by getting more power from outside. And in relation to Tres Amigas, I said in an earlier post, "Access to power from other grids when the Texas grid is short of power will prevent blackouts and increase the reliability of the (Texas) grid (to deliver power to its customers)".

Ultimately, whether the power customer is sitting in the dark or not is what really defines a reliable grid for people, not whether all the transmission equipment is intact.

Of course, isolation can also be a strength in other circumstances.

I know of two instances within my life time where grid-related issues caused an entire system in other parts of the country to shut down for a number of days. I would rather have rolling blackouts (because not all of the coal-burning plants are online) than that.

If a grid our grid is hooked up to goes down, our grid goes down with it.

Jeanette Isabelle

There is also the problem of Black Start if a wide area grid outage occurs.

A terrorist network attack of the electrical grid targeting the transmission lines from black start generator sets could be absolutely devastating to a countries economy enough to cause chaos from many a megacity (which itself could cause other Megacities to fail esp if the initial targeted Megacity was a finance centre) , the clock may easily get past that 3-4 days grace. 7+ days could be extremely challenging.

Knocking over the grid initially would be relativity simple especially during the high heat of the summer.

http://www.youtube.com/watch?v=BGJHwzsPdpY