Apples, oranges, and consistent comparisons of the temporal dynamics of energy transitions

Benjamin Sovacool (2016) has provided interesting food for thought in asking “how long will it take?” for the unfolding of energy transitions. Historical evidence of “grand” or global energy system transitions taking decades to centuries to unfold contrasted with highly selective recent and rapid examples of mostly incremental technological change make for an engaging argument. But the observed contrasts are due to the apples-and-oranges comparison between transitions that are measured differently, defined differently, characterized by different processes, and explained differently.