Monthly Archives: April 2012


Last week I talked about energy density and energy surpluses and how these factors dictate the arrangements of living that a given society can create.

Throughout history, humans have sought to increase energy surpluses, and nothing has fit the bill quite as well as fossil fuels. Traditionally, cities operated on modest energy surpluses provided by renewable sources of energy. However, during the Industrial Revolution technological developments unlocked huge energy surpluses embodied in non-renewable resources.

Since then, the process of replacing authentic ways of life based on sun, wind, and wave power collected regionally with a metastatic way of life based on natural gas, coal, and oil collected globally has been constant, mercurial, and sweeping.

It’s worth repeating that this transition to non-renewable resources was a no-brainer. Fossil fuels offered far more short-terms benefits than renewable sources, particularly with regard to energy density. In short, fossil fuels provided the Western world with a monumental energy surplus which it utilized to construct a massive industrial economy, and later, a tremendous number of energy-hungry metastatic cities.

Today all planners worth their salt see the folly in so whole-heartedly adopting an arrangement of living so beholden to and utterly dependent upon sources of energy which are clearly becoming increasingly expensive, difficult to recover, and scarce. It’s truly a tenuous predicament.

Most of those same planners also believe that metastatic cities can be reformed through efficiency measures and renewable energy production schemes. I’m much less sanguine on the prospect for the simple reason that the energy density of renewable sources is much too low to sustain arrangements of living designed to require massive and constant supplies of energy.

For the record I do believe metastatic cities will be converting to renewable energy sources in the not-to-distant future. However, I’m not sure it will be in the form that many subscribers to the insular planning paradigm expect.

But this week I’m not going to talk about the nuances of renewable energy or efficiency measures. Instead, I’m going to drill down a little further and elucidate the extent to which our metastatic cities are irredeemably energy-hungry – and by extension, hooked on fossil fuels.

One of the issues I always seem to run into when discussing urban sustainability issues with other planners is that they seem to discount the significance of the predicament metastatic cities face. Eventually it occurred to me that many well-meaning peers of mine are simply not conversant in physical and natural laws – or, as I like to call them – the laws of the jungle. These laws, which include the operational principles of dynamic dissipative systems, ecology, and thermodynamics describe how cities operate on a fundamental level.

However, physical and natural laws are not taught as part of conventional planning programs. Nor do they enter into the decision-making processes within government. They aren’t considered in land use decision-making processes by local land use boards, and so on. For all intents and purposes, planning decisions are informed by political, commercial and social actors.

I suppose this ignorance of physical and natural laws wouldn’t be a problem if energy was plentiful and ecological limits were a ways off. But as things stand now that’s simply not the case. The gap between how systems and ecological science tell us cities work and how insular planning policies assume cities work is widening.

It’s not my intention to levy detailed criticism upon insular planning strategies in this post. For now I’ll simply contend that many of these strategies start from flawed premises, and so can’t help but lead to flawed conclusions: garbage in, garbage out.

So, it’s not altogether surprising that planners discount the gravity of metastastic cities’ dilemma: they lack the interdisciplinary perspective which makes a clear understanding of the big picture possible.

Examining metastatic cities’ energy requirements will go a long way toward sharpening that big picture perspective. Much like we humans consume food so that our bodies may function, cities too require energy inputs to function. If a person consumes more calories than they burn, they gain weight. If they consume fewer calories than they burn, they lose weight. If they chronically eat fewer calories than they burn, they become frail.

This metabolism analogy carries over to cities as well, because human bodies and cities are both dynamic dissipative systems. As I discussed earlier, all dynamic dissipative systems require energy inputs, and the complexity of metastatic cities is wholly dependent upon the large inputs of energy they require to function. Quite simply, the metastatic city can be thought of as an enormous furnace which burns fossil fuels. And without the input of fossil fuels and the vast energy surplus they provide, metastatic cities would devolve into a state of frailty.

The metastatic city is comprised of social, technological, physical, and economic flow structures which consume energy over the course of daily operations. These actions include everything from the shipment of consumer goods via tractor trailer to making coffee in the morning, and everything in between. In short, every activity performed in the city requires energy inputs; no energy inputs, no functions.

Adding up all the diverse ways that metastatic cities consume energy is an excessively arduous task. A proxy for determining the energy requirements of metastatic cities can be obtained by multiplying the average American’s energy consumption by the population of the city in question. By coming at the problem from this other direction we can begin to conceive of the metastatic city’s metabolism in rough terms.

For instance, within a hunting and gathering way of life, humans require about 3,000 calories per day to perform daily activities. That arrangement of living provides very little in the way of energy surplus; that’s why these societies literally live on a hand to mouth basis.

In contrast, the average American requires 214 million calories per day to perform his daily activities. The extravagance of this metastatic arrangement of living is only possible with the massive energy surplus fossil fuels provide.

So just how big is the energy subsidy that fossil fuels provide? Well, it takes approximately 1,000 square feet of soil to produce enough food to feed one person 3,000 calories per day for the whole year. To supply 214 million calories per day per person for a whole year it would take approximately 86,500 square feet of soil!

If you applied these figures to the population of the Washington, DC metropolitan statistical area (MSA), you would find this one city would require 16,620 square miles of soil to supply its citizens with this sort of energy consumption if provided in strictly renewable terms. That would be problematic as the Washington, DC MSA contains only 5,564 square miles total. In other words, the area of soil needed to support a metastatic arrangement of living is three times the total area of the region.

Of course, the Washington region contains very little farmland. The amount of additional farmland that would be required to yield equivalent available energy content to what is being obtained from fossil fuel is called ghost acreage. This ghost acreage that supports Washington, DC obviously doesn’t exist; it’s an abstract concept which embodies the city’s high level of dependence on fossil fuel inputs.

There are other ways we can consider the unsustainability of the metastatic way of life – not in abstract terms like calories but in the much more tangible terms of human labor and sweat. For example, every moment of every day there are countless machines running on energy supplied by fossil fuel in metastatic cities: either directly as in automobiles or indirectly through the city’s infrastructure, including coal-fired supplies of electricity. Those machines are essentially performing tasks that would otherwise have to be performed by human or draft animal muscle power one way or another.

These fossil fuel-powered machines have effectively replaced human labor in today’s metastatic city thereby freeing up millions of man hours to accomplish other tasks. It’s as if each of us has a personal army working behind the scenes to keep our ice cubes cold, lights blazing, clothes clean, and so on. If we denominated the average metastatic city’s total energy consumption into terms measured in labor and sweat, we would find 140 “energy slaves” working for each of us behind the scenes, 24 hours a day, nonstop. The term energy slave is a metaphor by which the value of fossil fuel energy is measured in terms of its human muscle-power equivalent.

Next I’ll explore the scale of our energy surplus from a strictly metabolic perspective. The average American man stands 5 feet, 10 inches tall and weighs 170 pounds. To support his body’s functions, he must ingest 2,500 calories per day. If he lives in a metastatic city, that same man requires 214 million to accomplish his daily activities. If that man’s full energy demands were reflected in his body size alone, he would be as large as a 60 ton sperm whale. In this way, citizens of metastatic cities have effectively morphed into giants roaming the landscape, voraciously consuming enormous amounts of energy to support a colossal lifestyle.

The term “Homo colossus” was coined by William Catton. He reserved it for modern human beings who are equipped with technology which grants them enormous power, greatly increases their per capita resource demands, and environmental impact.

And what else can you call a city inhabited by legions of Homo Colossus but Colossusopolis? The fact that the Earth currently supports so many metastatic cities is incredible; it’s perhaps more incredible to assume the Earth will be able to support 2 billion more metastatic city dwellers by mid-century.

Perhaps I lack imagination, but it’s impossible for me to square up this tremendous (and growing) scale of resource consumption with the limitations of a finite planet in light of environment change and the ongoing expiration of easily-available and cheap fossil fuel supplies.

It’s reasons like this why I’m so down on policies that attempt to work backward from the status quo. Insular planning policies urging efficiency and renewable energy will prove inadequate to dealing with the full menu of challenges laid out before us. It’s a bummer, but there will be no comfy transition to a world full of increasingly dense, technologically-intensive, affluent, and ‘green’ Metastatic cities. The world simply cannot continue to support colossal extravagance.

The fact is that nature will compel us to transition to a less energy and resource intensive arrangement of living one way or another. And it will not come without sacrifices.

It’s high time we got serious about planning adequately for the predicament we face. First however, I’m going to take the next couple of posts to scrutinize insular planning policies under the harsh light of physical and natural laws. In so doing I hope to comprehensively identify, clarify, and expound upon what I believe to be their pernicious flaws. Only then can I set about proposing sufficiency planning guidelines that align with the scale of the predicament before us.

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City, Interrupted

Last week I finished up discussing the laws of the jungle – those laws of nature including system dynamics, thermodynamics, and ecological principles which govern both the operations of nature and cities.

For many of my readers it was a long slog through territories of thought and consideration not usually frequented by planners. And that’s a shame, because the laws of the jungle provide important and fundamental insights on how cities work on a constitutive basis.

I showed that there can be no discussion of cities’ relationship to ecological systems without discussing flows of available energy, as the city uses available energy to make its processes possible. Yet conventional thinking in the planning community suggests that cities are free of controlling principles beyond those that are legally, politically, and socially proscribed. The laws of the jungle show this to be untrue. The evidence of history shows us that human culture adapts its attitudes and choices to fit the reality of the energy transformation system and its hierarchy, and that people may attempt to build any type of society they like, but unless their plans take ecology into consideration, they will fail. What can and cannot be done is ultimately determined by energy laws.

I showed how available energy makes complexity possible for the city. Complexity is a system’s ability to maintain and replace flow structure, which itself refers to the social, technological, economic, and physical organization of society in terms of its population, occupations, diversity, institutions, and functions.

The quantity of available energy determines the complexity that can exist and the speed at which processes can function. In other words, complexity is the degree to which a city imposes its own order upon nature: the more available energy, the more imposed order; the less available energy, the less imposed order. With declining energy inputs, the operations of cities become ‘interrupted’, and with the absence of energy inputs, cities would quickly revert back to natural areas.

Additionally, I showed how the laws of the jungle can be used to properly evaluate and comprehend the dimensions of the predicament before us, and how they can provide a framework for sufficiency planning going forward.

Before we start laying out the framework for sufficiency planning in earnest however, this week it’s important to lay out why metastatic cities are so at risk as we enter the Age of Sufficiency. As a reminder, metastatic cities are cities which fail to operate within the limits of the resources and waste sinks available regionally. That definition drags just about every Western city into its wheelhouse, as well as many cities in the developing world that are forfeiting historically durable arrangements of living for  Western levels of consumption, prowess, modernity, and stature.

Unfortunately however, the newest entrants in this exuberant way of life have arrived to the party a bit too late. Today, the extraction of fossil fuels – including coal, oil, and natural gas – has provided us with a spectacular store of available energy which is no longer increasing, but has now reached a plateau and will begin dropping off at a time when demand is expected to increase substantially. These limits to growth will present fantastic challenges to a way of life utterly dependent upon large flows of cheap and easy-to-recover fossil fuels.

But I’m getting ahead of things a bit. Like so many other subjects, the best way to understand the weaknesses of metastatic cities is to start at the beginning to see how we got to where we are.

Over the course of history, humans have always focused on securing necessary available energy, and for most of that history it proved to be a difficult task. In their nascent stages, humans collected vegetables and captured animals that were available regionally for food. Twelve thousand years ago humans arranged for the growth of certain kinds of edible vegetation, and later humans began harnessing wind and water flows to add still more available energy.

Five thousand years ago, humans began selecting and planting edible vegetation in a deliberately intensive fashion. This breakthrough established a much more substantial energy surplus, and a much greater fraction of the populace was able to specialize in tasks that didn’t involve food production. Eventually, humans improved food production processes to such a degree that large and densely organized populations could be supported and the city was born.

By today’s standards, most cities over much of human history were fairly modest enterprises. That’s because the sources of energy that they depended upon provided only a very modest energy surplus. That’s not by accident.

Renewable forms of available energy – sun, wind, and wave power – have very specific properties. For starters, they come in flows, which means they can only be used at the rate they come in at. Second, they’re diffuse and difficult to collect. Third, renewable energy is difficult to store efficiently. Fourth, they have low power. Lastly, and perhaps most importantly, they possess low energy density.

The size and complexity of these cities were necessarily inhibited by the ecological limits imposed by the regions they inhabited. Regardless of these limitations however, humans managed to construct and establish sufficiently complex, beautiful, and exceedingly liveable cities over the centuries.

These authentic cities provided an atmosphere conducive to the formation of rich cultures and breakthroughs in science, art, and philosophy. “Authentic city” is my term for an ecologically-harmonious way of living within the limits of a given region.

Authentic cities conform to a set of very general, time-tested operating principles. For example, they solve local problems with locationally-appropriate solutions. They consume products and resources in keeping with what can be produced and harvested locally. Their citizens fiercely defend the ecological health of the region from exploitation, as they recognize it as the indisputable source of their livelihood. In short, they enable all citizens to meet their own needs and to enhance their well-being, without degrading the natural world or the lives of other people, now or in the future.

These humble, yet sufficiently stimulating arrangements of living flourished for thousands of years across multiple continents. Yet with the discovery of fossil fuels and the advent of fossil fuel-utilizing technologies, this way of life gave way in a historical instant to the metastatic arrangements of living we see today all over the world.

The main differentiating factor between the authentic city and the metastatic city is the source of their available energy. Whereas authentic cities depended upon the modest energy surpluses afforded by renewable sources, metastatic cities increasingly exploited the enormous energy surpluses bestowed by non-renewable resources including natural gas, oil, and coal.

Fossil fuels offered huge advantages over renewable sources which made the decision to exploit them obvious. For one thing, fossil fuels come in stores as opposed to flows. This is important because stores of energy can be utilized at a flexible rate. Second, they comes in solids, liquids, and gases, and are relatively easy to collect. Third, fossil fuels are easy to store and distribute. Fourth, they possess high power content. Lastly, and most importantly, they have much higher energy density than renewable sources. This last point is vital, so I’m going to spend a moment on it.

Energy density is a term used for the amount of energy stored in a space per unit volume. For example, gasoline has high energy density. Think about it: for $4 and change, one gallon can speed you, your friends, and a whole lot of stuff a distance of 25-30 miles. Imagine trying to convince someone to push your car around for 25-30 miles for $4 and see how far you get. Good luck with that!

In fact, gasoline’s energy density is so high that one gallon contains the energy equivalent to three weeks of one human’s non-stop work (at .074 kWH) or roughly one week of non-stop stair climbing (at .148 kWH). 32 gallons of gasoline releases energy equal to the energy content of the food an active human adult would consume in a full year.

When the implications of high energy density are grasped, it becomes clear why Westerners have thoroughly substituted fossil fuel-utilizing technologies for tasks once performed by muscle power, and why those in the developing world seek to do the same.

One result of this massive shift of dependence from renewable to non-renewable resources has left us with a way of life predicated on using extravagant sums of available energy. Another result of this shift is the creation of the predicament we currently face: increasingly numerous and voracious metastatic cities mottling the face of the Earth at the same time the fossil fuel supplies they depend upon are plateauing.

That’s not a great place to be, and so naturally the conversation in planning circles has begun to revolve around substituting in efficient buildings and transportation modes for wasteful and polluting fossil fuel-based buildings and transportation modes.

That’s all well and fine, and I for one support these initiatives to the extent that they recognize that renewable energy and efficiency measures will not provide nearly enough energy to maintain the metastatic way of life to which we’ve become accustomed. The laws of the jungle just won’t allow us to sustain the unsustainable, regardless of how much we want it.

The awkward fact is that renewable sources of energy still have the same limitations today which prevented the Romans from building expressways, skyscrapers, and jet planes thousands of years ago: they simply don’t have the energy density to make it happen, and that’s despite all the technological innovations that occurred over the same stretch of time.

Correspondingly, renewable sources will not be able to maintain our metastatic cities in their current form. Once fossil fuels enter terminal decline and energy descent begins to bite, the daily activities of those in metastatic cities will become ‘interrupted’. And yes, we will switch to renewable energy in response, but it’s not going to resemble anything like the slick promotional sketches promulgated by purveyors of insular planning strategies. That’s not politics talking, that’s the laws of the jungle talking: the energy just isn’t there.

There’s still quite a bit of wiggle room in terms of what energy descent will look like on the ground, and that’s where sufficiency planning best practices come into the picture. The question becomes how we can maintain a sufficiently-high quality of life with many fewer energy inputs.

I’m confident that the transition can occur if for no other reason than knowing that our ancestors lived on modest energy surpluses for millennia. If we’re smart about the transition – and by smart I mean observant of the laws of the jungle – we can make it.

But, alas that is a subject for another week. Before I get to all that, I’m going to show you just how bloated the energy demands are for metastatic arrangements of living. That’s where I’ll pick things up next week.