Sometimes a brilliant scientist, working alone, discovers something very, very important and nobody notices.
Human civilization depends on food, food depends on weather, and weather depends on climate. Every grain and every mammal on the face of the earth – almost everything we eat – evolved under a different climate than the one we're heading toward. We are running toward a cliff, and merely walking toward that cliff isn't a viable strategy. We need to stop. Right now.
If civilization is to survive, we need to get to zero emission of fossil carbon, and we need to get there rapidly. Every ton of carbon we emit stays in the air for centuries, and will continue to warm the planet for centuries.
In this series GETTING TO ZERO we will take a very hard-headed look at current energy policy and energy strategies. We will ask hard questions: does this really get us to zero? How much would it cost? How rapidly can it be deployed? We may find some answers along the way, but don't expect them to be easy.
This diary is part III of GETTING TO ZERO: Our non-fossil energy future.
Part I of GETTING TO ZERO can be found here.
Part II of GETTING TO ZERO can be found here.
There are a lot of strategies for getting us to zero fossil fuels, and nearly every one of them features increased energy efficiency as a key component. The IPCC thinks so; the International Energy Agency agrees; efficiency is one of the famous "Climate Wedges" from Princeton; it's a key strategy of Amory Lovins' Rocky Mountain Institute; renewables guru Mark Z. Jacobson relies on efficiency for energy demand reductions of 30% to 40%, more than any other emissions strategy. And the list goes on.
There's just one problem. They are all completely and totally wrong. Increasing energy efficiency does not, has not, and will not ever reduce overall demand for energy. This is not just an opinion; it has been demonstrated with the cold hard equations of physics, based on the second law of thermodynamics.
Now don't get me wrong. Energy efficiency has obvious economic benefits, and those benefits are often enough to make such improvements worthwhile. It's not that we should stop being more efficient. It's just that we should not expect those improvements to reduce energy demand or carbon emissions. Because they won't do that.
The reason efficiency doesn't actually reduce energy demand is because of what's called the rebound effect (sometimes called the Jevons Effect, or Jevons Paradox, after its discoverer). The issue is this: if we're doing some economic activity -- let's call it Activity X -- that activity will take a certain amount of energy. If we then discover a more efficient way of doing Activity X, it will use less energy. But that will also make Activity X cheaper to do, and by the law of supply and demand, when something gets cheaper demand for it will go up. That's called the primary rebound, or direct rebound. What most people (even most economists, who study this sort of thing) miss is that there is also a "secondary rebound", in which the money saved by the newly efficient Activity X goes instead to buy more of Activity Y and Activity Z. In other words, the efficiency improvement results in a net economic improvement, and the improved economy demands more energy. When you include the secondary effects, that eliminates all of the energy reductions, and more.
So, are all these smart people, like the IPCC and the Rocky Mountain Institute, unaware of the rebound? Of course not. There are dozens of academic papers about efficiency rebound, with dozens of little case studies of this or that efficiency improvement, tracking what did and didn't happen next. One problem is that most of these studies are done by economists, and nearly all of them look only at the primary rebound and not the secondary one. That's because it turns out to be really, really hard to track all the effects of an efficiency improvement all the way through the whole economy and make sure you've got them all. So most don't even try, and even the ones who do try miss things. The result is that nearly every study that looks at rebound comes up with a figure of, say, 20% or 40% or even 60% for the rebound, which still leaves a healthy margin for some energy/emissions reduction from efficiency gains.
And the other problem is, sometimes a brilliant scientist, working alone, discovers something very, very important and nobody notices. As in this case.
Dr. Timothy J. Garrett is an atmospheric scientist at the University of Utah, and climate change has been at the forefront of his work for a long time. Being a physicist, he takes a physicist's view of things. Some years ago, he developed a new framework for studying broad, long-term issues of civilization and climate: he conceived of human civilization, all of it, as one gigantic thermodynamic heat engine, and applied the basic laws of thermodynamics to civilization as a whole. Instead of looking very closely at the trees, Garrett sees the forest. The implications of that view are profound, and not particularly cheering.
The bottom line from Garrett's equations is that increasing the energy efficiency of civilization as a whole must necessarily also increase economic activity by similar amounts, which will result in no overall energy reduction at all -- ever -- from energy efficiency. The rebound effect cannot be less than 100%. If we are relying on energy efficiency to save us, that reliance is doomed to failure.
Garrett's work implies that there is one and only one strategy that can save our climate, and our civilization from self-destruction. We must switch energy sources away from fossil fuels, and rapidly.
One final note. Last week, the New York Times published an op-ed by Michael Schellenberger and Ted Nordhaus of The Breakthrough Institute (BTI) discussing the rebound effect and its implication that energy efficiency is inadequate as an emission reduction strategy. That op-ed prompted a secondary posting at The Energy Collective (TEC) by BTI's Jesse Jenkins, which in turn prompted a strong reply in favor of efficiency by the NRDC (Natural Resources Defense Council). Not one of these knowledgeable people or institutes mentioned Garrett's work.
But I did mention Garrett, repeatedly, in the comment threads to these TEC postings. One of the commenters to Jenkins' post was NRDC's resident physicist, David Goldstein, who initially claimed that studies showing rebound effects were non-falsifiable (and therefore not scientific). When I informed him of Garrett's work, based as it is in physics and thermodynamics, he had no reply.
References
For those who want to dig into the equations, here are the key papers:
Garrett, T. J. (2011). Are there basic physical constraints on future anthropogenic emissions of carbon dioxide?. Climatic change, 104(3-4), 437-455.
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.