Reading through George Monbiot’s Heat, I encountered the idea of the Khazzoom-Brookes Postulate for the first time. The postulate relates to the effect of increasing energy efficiency on total energy usage and holds thas as the energy efficiency of industrial processes increases, total energy use actually rises as well. While initially counter-intuitive, the idea does seem to have some validity. If the energy cost of producing one tonne of aluminum falls from $5000 to $4000, you would expect aluminum companies to produce more. After all, their profit margin will have widened, all else being the same. The Celsias blog cites another example: if Boeing’s new 787 Dreamliner is 20% more fuel efficient, that just means that ticket prices will fall and more people will fly. Greenhouse gas emissions will stay the same or rise.
As Monbiot acknowledges, the postulate is controversial. It is certainly decidedly inconvenient for all the people who trot out ‘increased energy efficiency’ as the first (painless) means to combat climate change. Increased energy efficiency may be great for various reasons of convenience and enjoyment, but the postulate and accompanying logic does give one reason to doubt whether it can have a positive effect on reducing greenhouse gas emissions.