14 Jun 2010

The Limits to Growth -- The Review

This 1972 book is subtitled "A report for the Club of Rome's Project on the Predicament of Mankind."

The collective authors -- much like the IPCC group -- wrote this book after meeting from 1968 to 1970. Their purpose was to work with the complexity of many trends -- poverty, environmental degredation, weakening institutions, urban sprawl, insecure employment, rejection of traditional values, inflation and so on. Their remit was to examine the factors that would limit growth: population, agricultural production, natural resources, industrial production and pollution. They used the most advanced computer models to map out the future dynamics of these five factors, as they influenced each other, with positive and negative feedback, over decades. (As you know, I am skeptical of models -- and especially of computer models -- but they can be useful as a means of visualizing interactions that are too complicated to describe.)

The Club concludes that:
  1. Current (1970!) behavior will limit growth within 100 years. "The most probable result will be a rather sudden and uncontrollable decline in both population and industrial capacity" [p 29]
  2. It's possible to avoid this result, to establish ecological and economic stability.
  3. If we want the second outcome, we'd better get to work.
This struck me as both prescient and sad. Since 1970, we have surely made some progress on natural resources and industrial & agricultural production, but we have not done very well on population control or pollution. Certainly not on the scale that the Club's authors suggested.

The main point of the book is that exponential growth (in pollution or population) will exhaust finite resources. This is a mathematical fact that the authors pound into the reader. (That doesn't mean that the reader will believe it!) And these folks do not just naively draw a exponential curve for the demand for minerals against a finite supply and then conclude that a shortage will result. They discuss the interaction of supply and demand and how those forces affect price and quantity in the market. So their reasoning is sound; they take limits and dynamic changes in behavior into account and THEN reach a dark conclusion.

Carbon wonks will be interested to know that the Club explicitly discusses CO2 as a pollutant that is being absorbed into the air and oceans, and how that CO2 will raise global temperatures. They predict (rather, hope) that nuclear power will displace fossil fuels before "the increase in atmospheric CO2 emissions... has any ecological or climatological effect." [p 87] They also say that they do not know how much CO2 can be absorbed without causing a response. We know now that the "no effect" threshold was passed a few years ago, perhaps at the same time as the report was issued.

As I flipped through the simulations, I was impressed by the analysis of binding constraints. (Like MIT guys need to impress me!) The basic idea is that you need keep all five factors (population, agricultural production, natural resources, industrial production and pollution) within a sustainable range. Get too much, and you crash; get too little and you crash. They conclude, e.g., that unlimited resources will not "fix" our problem because pollution will get out of control. (Something I said 25 years later :)

They also pour cold water on the silver bullet: "technological optimism is the most common and the most dangerous reaction to our findings from the world model. Technology can relieve the symptoms of a problem without affecting the underlying causes. Faith in technology as the ultimate solution to all problems can thus divert our attention from the most fundamental problem -- the problem of growth in a finite system -- and prevent us from taking effective action to solve it." [p 159] Their solution? Limit our activities to a sustainable level.

Bottom Line: This book got a lot of attention nearly 40 years ago. Too bad that we haven't implemented its recommendations. We are still running towards that cliff of "rather sudden and uncontrollable decline in both population and industrial capacity." Can we stop the committees and inquiries and take some actions? I give this book FIVE STARS for being clear and relevant; I give its readers ONE STAR for failing to follow through.