Energy and Human Ambitions on a Finite Planet, 2021a

2 Economic Growth Limits 23
as a vital substance. 13 Marketers might sell H 2 O 2 as superior, having
one more beneficial oxygen atom, but please don’t drink hydrogen peroxide!
Some technologies in use today would be recognized by pre-industrial
people: wheels, string, bowls, glass, clothing. We won’t always find better
things, though we may make a series of incremental improvements over
time. Not everything will experience game-changing developments.
13: Relatedly, consider that the Periodic Table
is finite <strong>and</strong> fits easily on a single sheet
of paper (Fig. B.1; p. 375). We don’t have an
unlimited set of substitute elements/compounds
available. Astrophysical measurements
validate that the whole universe is
limited to the same set of elements.
In summary, decoupling <strong>and</strong> substitution are touted as mechanisms
by which economic growth need not slow down as energy <strong>and</strong> other
resources become constrained. We can make money using less of the
resource (decoupling) or just find alternatives that are not constrained
(substitution), the thinking goes. And yes, this is backed up by loads
of examples where such things have happened. It would be foolish to
claim that we have reached the end of the line <strong>and</strong> can expect no more
gains from decoupling or substitution. But it would be equally foolish
to imagine that they can produce dividends eternally so that economic
growth is a permanent condition.
Box 2.3: Efficiency Limits
Efficiency improvements would seem to offer a way to tolerate a
stagnation or decline in available energy resources. Getting more
from less is very appealing. Yes, efficiency improvements are good
<strong>and</strong> should be pursued. But they are no answer to growth limits, for
the following reasons.
1. For the most part, realized efficiencies are already within a
factor-of-two of theoretical limits. 14 A motor or generator operating
at 90% efficiency has little room to improve. If efficiencies limits for thermal sources like fossil fuels.
14: Chapter 6 covers theoretical efficiency
were typically far smaller than 1%, it would be reasonable to
seek improvements as a “resource” for some time to come, but
that is not the lay of the l<strong>and</strong>.
2. Efficiency improvements in energy use tend to creep along at
∼1% per year, 15 15: . . . meaning 30% one year might be
or sometimes 2%. Doubling times are therefore 30.3% next year (not 31%, which would
measured in decades, which combined with the previous point be a ∼3% improvement)
suggests an end to this train ride within the century. 16
16: . . . similar to lighting technology, as per
3. Efficiency improvements can backfire, in a process called the Box 2.1 <strong>and</strong> Figure 2.3
Jevons paradox or the rebound effect. Increased dem<strong>and</strong> for
the more efficient technology results in greater dem<strong>and</strong> for the
underlying resource. For example, improvements in refrigerator
efficiency resulted in larger refrigerators <strong>and</strong> more of them, 17
for a net increase in energy devoted to refrigeration. Consider
that per-capita global energy <strong>and</strong> material resource use has
climbed inexorably amidst a backdrop of substantial efficiency
improvements over the last century [12].
Efficiency improvements are not capable of resolving resource dem<strong>and</strong>.
17: . . . e.g., in basements or garages or offices
[12]: Garret (2014), Rebound, Backfire, <strong>and</strong> the
Jevons Paradox
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.