As energy efficiency increases, civilization grows faster, consumes more resources faster, grows the economy: The bad news — Energy consumption and CO2 emissions accelerate.
No 2393 Posted by fw, November 9, 2018
NOTE — To access my other posts related to Dr. Garrett’s research on a global economic/civilization collapse by the end of this century, click on the Tab in the top left margin, titled Civilization/Economic Collapse ~ Links to All Posts By or About Dr. Tim Garrett’s Research
“Improving energy efficiency is our best hope to slow global energy consumption and limit carbon dioxide emissions. Makes perfect sense, right? Better technology for more jobs and a healthier planet! Yay capitalism. But let’s look a little closer. … It is easy to find economists … pointing to … examples in economic sectors or nations where energy efficiency gains have led to less energy consumption. For example, the USA has become more efficient and thereby stabilized its rate of energy consumption. While these counter-examples may be true, they are also very misleading, especially if the subject is climate change. … Taking this global perspective with respect to the economy, efficiency gains will do the exact opposite of what efficiency policy advocates claim it will do. If technological changes allow global energy productivity or energy efficiency to increase, then civilization will grow faster into the resources that sustain it. This grows the economy, but it also means that energy consumption and CO2 emissions accelerate. CO2 emissions can be stabilized despite efficiency gains. But this is possible only if decarbonization occurs as quickly as energy consumption grows. At today’s consumption growth rates, this would require roughly one new nuclear power plant, or equivalent in renewables, to be deployed each day.” —Tim Garrett, Nephologue
The above passage captures the essence of atmospheric physicist Tim Garrett’s article, reposted in full below. In addition, at the bottom of the post is a link to a related paper, also by Garrett, to which I have reposted the paper’s abstract.
To read Garrett’s energy efficiency article on his blog, Nephologue, click on the following linked title.
Improving energy efficiency is our best hope to slow global energy consumption and limit carbon dioxide emissions.
Makes perfect sense, right? Better technology for more jobs and a healthier planet! Yay capitalism.
But let’s look a little closer. People may choose to drive more often if a vehicle is fuel efficient: driving is useful or pleasurable and now it is more affordable. Or, less money spent on fueling energy efficient vehicles could enable more money to be spent on fuel for home air conditioning.
The idea was first introduced by William Stanley Jevons in 1865. Jevons was emphatic that energy efficient steam engines had accelerated Britain’s consumption of coal. The cost of steam-powered coal extraction became cheaper and, because coal was very useful, more attractive.
Economists do acknowledge this to some degree referring to a phenomenon called “rebound”. A very few studies even argue for “backfire”: gains in energy efficiency ultimately lead to greater energy consumption. Calculating the total magnitude of rebound or backfire has proved contentious and elusive. The problem for academics has been that any given efficiency improvement has knock-on effects that can eventually propagate through the entire global economy. Estimating the ultimate impact is daunting if not impossible.
Imagine you buy a nice new fuel efficient car. An unequivocal good for the environment, right? Sure feels good to do one’s part to save the planet. And you have a fatter wallet too since you spend less on gas. Life’s good! You can spend that saved money now (for argument’s sake) on better household heating and cooling so that you sleep better at nights. Being more rested you become more productive at work, giving you a raise and your employer higher profits. The business grows to consume more while you take that much deserved flight for a vacation in Cancun.
In this fashion, the ramifications of any given efficiency action might multiply indefinitely, spreading at a variety of rates throughout the global economy. Barring global analysis over long time scales, conclusions about the magnitude of rebound or backfire may be quantitative but highly uncertain since they are always dependent on the time and spatial scales considered.
Analyzing the global economy like a growing child
There’s a way around this complexity — ignore it by treating the economy only as a whole.
Stepping back like this is a standard part of the physics toolbox. Imagine describing the growth of a child without being an expert in physiology. It shouldn’t take a doctor to comprehend that the child uses the material nutrients and potential energy in food not only to produce waste but also to grow its body mass. As the child grows, it needs to eat more food, accelerating its growth until it reaches adulthood and its growth stabilizes (hopefully!).
Now, an inefficient, diseased child who cannot successfully turn food to body mass may become sickly, lose weight, and even die. But a healthy, energy efficient child will continue to grow and some day become a robust adult who consumes food energy at a much higher rate than as an infant.
What could be treated as a tremendously complicated problem can also be approached in a fairly straight-forward manner, provided we look at the child as a complete person and not just a complex machine of component body parts.
Efficient civilization growth
We can take the same perspective with civilization. Without a doubt, consuming energy is what allows for all of civilization’s activities and circulations to continue — without potential energy dissipation* nothing in the economy can happen; even our thoughts and choices require energy consumption for electrical signals to cross neural synapses. Just like a child, when civilization is efficient it is able to use a fraction of this energy in order to incorporate new raw materials into its structure. It was by being efficient that civilization was able to increase its size.
[*In this paragraph, Tim essentially defines ‘dissipation’]. When civilization expands, it increases its ability to access reserves of primary energy and raw materials, provided they remain or are there to be discovered. Increased access to energy reserves allows civilization to sustain its newly added circulations. If this efficiency is sustained, civilization can continue to grow. In a positive feedback loop, expansion work leads to greater energy inputs, more work, and more rapid expansion.
This is the feedback that is the recipe for emergent growth, not just of civilization, or a child, but of any system. The more efficiently energy is consumed, the faster the system grows, and the more rapidly the system grows its energy consumption needs.
Ultimately there are constraints on efficiency and growth from reserve depletion and internal decay. But in the growth phase, efficient conversion of energy to work allows civilization to become both more prosperous and more consumptive.
Implications for climate change
It is easy to find economists willing to express disdain for the concept of backfire, or even rebound, by pointing to counter-examples in economic sectors or nations where energy efficiency gains have led to less energy consumption. For example, the USA has become more efficient and thereby stabilized its rate of energy consumption.
While these counter-examples may be true, they are also very misleading, especially if the subject is climate change. Nations do not exist in economic isolation. Through international trade the world shares and competes for collective resources. Quite plausibly, the only reason the USA appears to consume less energy is that it has outsourced the more energy intensive aspects of its economy to countries like China. Should an economist argue that “There is nothing particularly magical about the macroeconomy, it is merely the sum of all the micro parts” we can be just as dismayed as we would upon hearing a medical practitioner state that “there is nothing particularly magical about the human body, it is merely the sum of all its internal organs”. Connections matter!
Fundamentally, through trade, civilization can be treated as being “well-mixed” over timescales relevant to economic growth. In other words, trade happens quickly compared to global economic growth rates of a couple of percent per year. Similarly, excess atmospheric concentrations of CO2 grow globally at a couple of percent per year. They too are well-mixed over timescales relevant to global warming forecasts because atmospheric circulations quickly connect one part of the atmosphere every other. For the purpose of relating the economy to atmospheric CO2 concentrations, the only thing that matters is global scale emissions by civilization as a whole.
Taking this global perspective with respect to the economy, efficiency gains will do the exact opposite of what efficiency policy advocates claim it will do. If technological changes allow global energy productivity or energy efficiency to increase, then civilization will grow faster into the resources that sustain it. This grows the economy, but it also means that energy consumption and CO2 emissions accelerate.
CO2 emissions can be stabilized despite efficiency gains. But this is possible only if decarbonization occurs as quickly as energy consumption grows. At today’s consumption growth rates, this would require roughly one new nuclear power plant, or equivalent in renewables, to be deployed each day.
For more details
Garrett, T. J., 2012: No way out? The double-bind in seeking global prosperity alongside mitigated climate change, Earth System Dynamics 3, 1-17, doi:10.5194/esd-3-1-2012
Abstract. In a prior study (Garrett, 2011), I introduced a simple economic growth model designed to be consistent with general thermodynamic laws. Unlike traditional economic models, civilization is viewed only as a well-mixed global whole with no distinction made between individual nations, economic sectors, labor, or capital investments. At the model core is a hypothesis that the global economy’s current rate of primary energy consumption is tied through a constant to a very general representation of its historically accumulated wealth. Observations support this hypothesis, and indicate that the constant’s value is λ = 9.7 ± 0.3 milliwatts per 1990 US dollar. It is this link that allows for treatment of seemingly complex economic systems as simple physical systems. Here, this growth model is coupled to a linear formulation for the evolution of globally well-mixed atmospheric CO2 concentrations. While very simple, the coupled model provides faithful multi-decadal hindcasts of trajectories in gross world product (GWP) and CO2. Extending the model to the future, the model suggests that the well-known IPCC SRES scenarios substantially underestimate how much CO2levels will rise for a given level of future economic prosperity. For one, global CO2 emission rates cannot be decoupled from wealth through efficiency gains. For another, like a long-term natural disaster, future greenhouse warming can be expected to act as an inflationary drag on the real growth of global wealth. For atmospheric CO2 concentrations to remain below a “dangerous” level of 450 ppmv (Hansen et al., 2007), model forecasts suggest that there will have to be some combination of an unrealistically rapid rate of energy decarbonization and nearly immediate reductions in global civilization wealth. Effectively, it appears that civilization may be in a double-bind. If civilization does not collapse quickly this century, then CO2 levels will likely end up exceeding 1000 ppmv; but, if CO2 levels rise by this much, then the risk is that civilization will gradually tend towards collapse.
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