Overly Simple Energy-Economy Models Give Misleading Answers

Does it make a difference if our models of energy and the economy are overly simple? I would argue that it depends on what we plan to use the models for. If all we want to do is determine approximately how many years in the future energy supplies will turn down, then a simple model is perfectly sufficient. But if we want to determine how we might change the current economy to make it hold up better against the forces it is facing, we need a more complex model that explains the economy’s real problems as we reach limits. We need a model that tells the correct shape of the curve, as well as the approximate timing. I suggest reading my recent post regarding complexity and its effects as background for this post.

The common lay interpretation of simple models is that running out of energy supplies can be expected to be our overwhelming problem in the future. A more complete model suggests that our problems as we approach limits are likely to be quite different: growing wealth disparity, inability to maintain complex infrastructure, and growing debt problems. Energy supplies that look easy to extract will not, in fact, be available because prices will not rise high enough. These problems can be expected to change the shape of the curve of future energy consumption to one with a fairly fast decline, such as the Seneca Cliff.

Figure 5. Seneca Cliff by Ugo Bardi

Figure 1. Seneca Cliff by Ugo Bardi. This curve is based on writings in the 1st century C.E. by Lucius Anneaus Seneca, “It would be of some consolation for the feebleness of our selves and our works if all things should perish as slowly as they come into being; but as it is, increases are of sluggish growth, but the way to ruin is rapid.”

It is not intuitive, but complexity-related issues create a situation in which economies need to grow, or they will collapse. See my post, The Physics of Energy and the Economy. The popular idea that we extract 50% of a resource before peak, and 50% after peak will be found not to be true–much of the second 50% will stay in the ground.

Some readers may be interested in a new article that I assisted in writing, relating to the role that price plays in the quantity of oil extracted. The article is called, “An oil production forecast for China considering economic limits.”  This article has been published by the academic journal Energy, and is available as a free download for 50 days.

A Simple Model Works If All We Are Trying to Do Is Make a Rough Estimate of the Date of the Downturn

Are we like the team that Dennis Meadows headed up in the early 1970s, simply trying to make a ballpark estimate of when natural resource limits are going to become a severe problem? (This analysis is the basis of the 1972 book, Limits to Growth.) Or are we like M. King Hubbert, back in 1956, trying to warn citizens about energy problems in the fairly distant future? In the case of Hubbert and Meadows, all that was needed was a fairly simple model, telling roughly when the problem might hit, but not necessarily in what way. Continue reading