Theory that Civilization is a Heat Engine

A University of Utah scientist (Tim Garrett, an associate professor of atmospheric sciences) argues that rising carbon dioxide emissions – the major cause of global warming – cannot be stabilized unless the world’s economy collapses or society builds the equivalent of one new nuclear power plant each day.

“Fundamentally, I believe the system is deterministic,” says Garrett. “Changes in population and standard of living are only a function of the current energy efficiency. That leaves only switching to a non-carbon-dioxide-emitting power source as an available option.”

“The problem is that, in order to stabilize emissions, not even reduce them, we have to switch to non-carbonized energy sources at a rate about 2.1 percent per year. That comes out to almost one new nuclear power plant per day.”

Garrett’s study was panned by some economists and rejected by several journals before acceptance by Climatic Change, a journal edited by renowned Stanford University climate scientist Stephen Schneider. The study will be published online this week.

The study – which is based on the concept that physics can be used to characterize the evolution of civilization – indicates:

* Energy conservation or efficiency doesn’t really save energy, but instead spurs economic growth and accelerated energy consumption.

* Throughout history, a simple physical “constant” – an unchanging mathematical value – links global energy use to the world’s accumulated economic productivity, adjusted for inflation. So it isn’t necessary to consider population growth and standard of living in predicting society’s future energy consumption and resulting carbon dioxide emissions.

* “Stabilization of carbon dioxide emissions at current rates will require approximately 300 gigawatts of new non-carbon-dioxide-emitting power production capacity annually – approximately one new nuclear power plant (or equivalent) per day,” Garrett says. “Physically, there are no other options without killing the economy.”

Garrett treats civilization like a “heat engine” that “consumes energy and does ‘work’ in the form of economic production, which then spurs it to consume more energy,” he says.

“If society consumed no energy, civilization would be worthless,” he adds. “It is only by consuming energy that civilization is able to maintain the activities that give it economic value. This means that if we ever start to run out of energy, then the value of civilization is going to fall and even collapse absent discovery of new energy sources.”

Garrett says his study’s key finding “is that accumulated economic production over the course of history has been tied to the rate of energy consumption at a global level through a constant factor.”

That “constant” is 9.7 (plus or minus 0.3) milliwatts per inflation-adjusted 1990 dollar. So if you look at economic and energy production at any specific time in history, “each inflation-adjusted 1990 dollar would be supported by 9.7 milliwatts of primary energy consumption,” Garrett says.

Garrett tested his theory and found this constant relationship between energy use and economic production at any given time by using United Nations statistics for global GDP (gross domestic product), U.S. Department of Energy data on global energy consumption during 1970-2005, and previous studies that estimated global economic production as long as 2,000 years ago. Then he investigated the implications for carbon dioxide emissions.

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