The correlation nobody explains away
In 1973, the price of oil quadrupled in three months. GDP in every industrialized nation fell. Unemployment rose. Inflation rose. The Keynesian models shattered on contact with a physical constraint. Most economics departments teach the oil shocks as a supply disruption. We teach them as the moment the discipline should have realized its models were missing a variable the size of the sun.
The correlation between energy and GDP is the most robust empirical relationship in economics. Across 200 years, across every country that industrialized, the elasticity is 0.6 to 0.7. A ten percent increase in energy use tracks a six to seven percent increase in output. The relationship survived two world wars, the information revolution, and the invention of derivatives. When economists claim the economy has decoupled
from energy, they mean the ratio improved. They do not mean — though the word implies — that you can have GDP without energy. You cannot. No civilization in history has.
The market traditionalists say the price mechanism captures our concern. We do not dispute the mechanism. We dispute the timescale. Markets optimize over quarters. Thermodynamic constraints operate over centuries. The degrowth camp shares our physics and draws a conclusion we resist: that the only honest response is shrinking the economy. We believe a civilization that transitions to 580 exajoules of nuclear and solar addresses the climate constraint without shrinking. Build the energy system correctly and the economy follows. Build it wrong — or pretend it doesn’t need one — and you get the situation we are in.
Where we concede ground: Japan uses half the energy per GDP unit that the US does. The difference is institutional, not thermodynamic.
What would change our mind: A major economy sustaining 3% GDP growth for two decades while cutting primary energy use 20%, with honest import accounting.
Read the full synthesis: Is energy the true currency?