If all of us in the planning community could agree that sustainability means to operate within the scope of what nature will allow indefinitely by using renewable resources at a rate slower than they are naturally replaced, and reducing non-renewable resource use faster than they are depleted, we could begin planning authentically sustainable cities from a foundation in ecological principles. Unfortunately, there remains much confusion about this subject because insular planning – the dominant planning model in effect today – is mired in outdated myths about how the world works and humans’ place in it.
The myth that humans are in charge of their destiny regardless of what Mother Nature has to say about it is reflected in insular planning’s faulty and much-referenced “3-Legged Stool” approach to sustainability. Though each of the three intersecting circles (social equity, economy, and environment) hold equal weight in the model, last week I pointed out the awkward fact that two of the circles – equity and economy – are wholly dependent upon the third – environment. This implies that humans can establish any kind of society and living arrangement they want so long as they function within the bounds of what nature will allow.
Unfortunately, the society and arrangement of living we have inherited in the Western world is one that promotes the Human Imperative instead – a syndrome of policies which strives to provide ever-greater standards of material comfort, wealth, and fossil fuel-dependent technologies upon an ever-greater number of people (but not all), regardless of the environmental cost.
It asserts that by mid-century we will add 2 billion people and grow our energy-intensive, consumer-based economy three times over on an infinite wave of cheap and readily-available resources and technological wizardry.
That’s an unfortunate ideology to be encumbered with just now as the ecological basis for our survival is undermined and the availability of cheap and easily-attainable energy supplies levels off instead. Yet in spite of these challenges, insular planning promotes a happy plan showcasing efficiency as the primary tool by which the Human Imperative and environmental restoration may be ensured.
The idea is that by increasing efficiency and renewable energy via ingenuity (i.e. technological progress) we can provide for a workable transition to a new arrangement of living comprising a world full of increasingly dense, technologically-intensive, affluent, and even ‘greener’ metropolises.
I don’t believe for a minute that there’s anything at all sustainable about this idea; it represents a whole lot of hand waving, ecological ignorance and magical thinking.
This week I intend to show you how a phenomenon called the rebound effect throws a long shadow of doubt over the illustrious claims made in the name of efficiency. In doing so, I’ll do my level best to avoid getting overly technical. I think you’ll find it’s a fairly straightforward concept to grasp.
The rebound effect is a term used to describe changes in levels of consumption of a resource when the efficient use of that resource improves. Very rarely does an improvement in efficiency result in an equal reduction in consumption. Much more commonly, a fraction of the savings is used to buy a greater amount of the resource.
For instance, if a 5% improvement in vehicle fuel efficiency results in only a 2% drop in fuel use, it would comprise a 60% rebound effect. The 3% difference might be reflected in longer driving distances or spent in another activity. Either way, it would prove quite unlikely that the 5% improvement in efficiency would result in an identical 5% reduction. Instead, consumption “rebounds” to account for the greater supply of the resource.
The rebound effect was first articulated by William Stanley Jevons, a British economist during the 19th century. In his 1865 book “The Coal Question” he famously explored whether energy efficiency all by itself leads to the hoped-for result of less energy consumption. This was a major concern in Britain at the time, as the Empire’s success rested upon the availability of cheap and easily-mined supplies of coal which were becoming increasingly scarce.
Some experts believed that coal scarcity was not an issue because use and production of steam engines was becoming more and more efficient. Jevons argued, seemingly paradoxically, that less fuel consumption per unit of equipment causes greater total consumption and that fuel can be saved per unit in the short term while not at all being spared for posterity’s sake.
Jevons’ discovery is not actually a paradox; instead, it has a basis in dynamic dissipative system behavior (which I’ll touch on in next week’s post). For now, I want to focus on the implications of Jevons’ discovery in light of that central tenet of insular planning’s sustainability strategy: efficiency.
Myth: “Greater efficiency will allow us to become less environmentally impactful and help grow our economy.”
Before we tackle this myth head on, it’s important to talk about what an efficiency comprises. In strictly physical terms, an efficiency is produced when more work for a given input of energy – or the same work for less input – or proportionately more work for an increase in energy input – is achieved. If I get 140 lumens out of a kilowatt of electricity, I will have achieved an efficiency when I get 160 lumens for that kilowatt, or when I get the same 140 lumens from 0.8 kilowatts, or when I get 170 lumens with 1.2 kilowatts.
The false premise of the myth above is that efficiency gains can be located in two places at once: both reinvested in the economic system (to benefit the economy) and retired from use (to benefit the environment). The truth in the matter is that when we realize an efficiency gain, we can either enrich ourselves (greater output with same input) or help the environment (same output with less input).
Over the course of the Age of Exuberance, we’ve chosen the “enriching ourselves” option. The growth and expansion of our cities and economies over the past 250 years can be almost completely attributed to the discovery and increasingly efficient exploitation of plentiful fossil fuels. During that time, technological processes improved greatly, thus freeing up energy which could be applied to other endeavors. If one ton of coal could now do what it took two tons of coal to do previously, that leftover ton of coal now became available for employment elsewhere in the economy.
In theory however, those efficiency gains could be retired, resulting in less work overall. This is what the Luddites were fearful of; they assumed that machines would replace them and they would not be able to secure further employment. What history has shown however is that the Luddites, much like the leftover ton of coal above, did find new employment, albeit not in their former occupation. They were not retired by efficiency but instead were re-employed within the economic system, all the while enlarging it.
Repeat that process time and again for a few centuries and it leads where we are today: ensconced within a super-specialized, massively-complex metastatic arrangement of living presently bumping up against limits to growth. This result comes as no surprise: the Human Imperative demands the re-investment of efficiency gains back into the system to provide greater economic growth, physical expansion, and system throughput at the expense of the environment.
This program has worked tolerably well thus far because environmental limits always seemed a good ways off. But that’s no longer the case: the limits on the environment side of things are beginning to assert themselves in the form of energy scarcity, ecological frailty and climate instability. As the Age of Sufficiency unfolds, these physical limits will increasingly put brakes on the Human Imperative.
Interestingly, insular planning doesn’t see it that way. Contrary to all historical and scientific evidence, it subscribes to the belief that efficiency of any sort serves as a tool for both lower environmental impact and increasing growth and affluence – in effect, increasing outputs while simultaneously reducing inputs.
It fails to recognize that a world full of increasingly dense, technologically-intensive, affluent metropolises on the one hand and a healthy, well-functioning biosphere are mutually-exclusive goals. In effect, insular planning expects to have its cake and eat it too.
Allow me to reiterate a point made earlier: there is nothing sustainable about reinvesting efficiency gains back into the system to provide exponentially increasing economic growth, physical expansion, and system throughput at the expense of our finite environment.
That statement holds even in instances when per capita energy consumption is falling. The rebound effect tells us that it’s entirely possible for per capita energy consumption to fall as total energy consumption rises. And efficiency does us no good if it’s not reducing energy consumption in real terms, because Mother Nature is only interested in raw totals.
And the raw totals for energy consumption, carbon pollution and other forms of environmental degradation have been going up since the beginning of the Industrial Revolution and particularly so since the end of World War II. And Mother Nature isn’t happy about it.
Now, if population, economic growth, and use of technology were purposely held in check for the foreseeable future, then per capita reductions in energy consumption of a certain degree would be satisfactory. But ready or not this planet is set to receive an additional 2 billion souls over the next 38 years, and the Human Imperative will attempt to outfit them with increasing wealth and technologies.
This imperative will surely eat into any per capita reductions in energy use, just as it has in the past. That’s the crux of the rebound effect problem: we have a society which encourages growth and expansion at all costs while living on a finite planet with some exceedingly rigid physical and ecological laws (which those same humans mistakenly dismiss as irrelevant to their interests).
In future posts I intend to lay out planning policies which recognize, account for, and nullify the rebound effect by retiring efficiency gains in the interest of environmental restoration.
In short, these policies will require curtailment; that is, paying more money for less energy and working less for less consumption. This is the only reliable way to ensure that energy consumption is reduced in real terms. It implies a revaluation of leisure time and other quality of life concerns over pursuit of the almighty dollar.
Additionally, these policies would steer our technological ingenuity not toward expanding the economy and degrading the environment, but toward figuring out how to get the best and most equitable life possible out of resources and energy available on a renewable basis. Given the average metastatic city’s level of overshoot, that would be a test of mind and skill.
In closing I leave you with these axioms with regard to efficiency:
- Efficiency first does not give frugality second; it makes frugality less necessary.
- Efficiency is a result of scarcity and never the cause of frugality.
- If we seek frugality first we get efficiency second as an adaptation to scarcity.
- Efficiency is an effect, not a cause.
- Efficiency is an end, not a means.
- Reinvesting efficiency gains back into the growth of the system at large will not serve our cities’ long term interests.
If you would like to read more about the rebound effect, please consult the excellent “The Myth of Resource Efficiency” by John Polimeni, et al., The Sufficiency Principle” by Thomas Princen, and “Energy Efficiency and Sustainable Consumption: The Rebound Effect” by Horace Herring and Steve Sorrell.