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 […]