Taking a short break--No post this week or next

I'm taking a short break this week and next and expect to post again on Sunday, October 5.

Are we on the path of 'Limits to Growth'?

Probably the most important thing you need to know about the 1972 book entitled Limits to Growth is that it makes no predictions. Rather, the much maligned study provides scenarios for thinking about the future of resource use, pollution, population, food, and industrial production.

Limits to Growth detailed three scenarios originally, one of them called business-as-usual or BAU. Since then, countless scenarios have been run using the same model--called World3--and some of them are discussed in updates to the book, the most recent published in 2004. Many of the scenarios including BAU result in a collapse of industrial production and population some time this century.

What has surprised those reviewing the model used by Limits to Growth researchers is how closely reality has tracked the original BAU scenario. A recent review suggests that the signs of societal collapse may be around the corner based on the observed trends. But the components of that model have yet to turn in deleterious directions which would suggest trouble.

The more uncertain we are, the more careful we should be

It is a staple of apologists for the chemical and fossil fuel industries to say, "We have no proof that what you are talking about is dangerous." Let me restate that in probabilistic terms: "We are highly uncertain about the harm of what you are talking about."

When stated in probabilistic terms, uncertainty about harm becomes much more alarming. Nassim Nicholas Taleb has added to a working paper which I discussed last week entitled "The Precautionary Principle: Fragility and Black Swans from Policy Actions." As I suggested in last week's piece, climate change is an obvious candidate for the precautionary principle because climate change involves the risk of systemic ruin.

In his addendum Taleb explains that climate change deniers who criticize climate models for their uncertainty don't have the slightest clue what that implies. Rather than suggesting that we should ignore such models, the uncertainty suggests that we should be even more diligent about mitigating climate change since the high uncertainty means, probabilisticly speaking, that we have larger exposure to catastrophic outcomes.