Thursday, February 10, 2011
Roger Pielke takes Energy Secretary Chu to task for supposedly having said "it’s a myth that the wealth of a country is proportional to its energy use." As evidence of the high degree of proportionately, Pielke presents the above Gapminder graph, showing the total GDP of a country (y-axis, measured at purchasing power parity) highly correlated with the total energy use (x-axis).
However, Pielke has used a couple of not altogether legitimate graphing tricks to overstate his point. Firstly, by using total GDP and total energy use, he spreads the points out further along the line, since very big countries will obviously, other things being equal, use much more energy and create much more GDP than very small countries. But when we say that a country has "wealth", we don't usually mean that it's big, we mean instead that the inhabitants are well off on average. So, sticking with Gapminder, if we switch to per-capita variables (GDP/capita on the y-axis, and CO emissions per person on the x-axis, since Gapminder won't do energy/capita) we get this:
Well, there certainly is a relationship still between wealth and fossil fuel usage. However, note that this is a log-log graph. If you look at the spread of the data in the x direction, you'll see that at any given wealth level, the lowest emitting countries are an order of magnitude better than the highest emitting countries.
So there clearly is enormous room for improvement in many high emitting countries, without becoming poor.