Improving energy efficiency is central to limiting energy demand growth, reducing emissions, and easing pressure on energy systems. However, the pace and sources of global progress remain poorly understood, particularly in relation to the COP28 pledge to double the global rate of energy-efficiency improvement from around 2% to 4% per year by 2030. Here, we assemble a global country-level panel of 185 countries for 1990-2024 and combine decomposition with a quantile-based frontier approach to distinguish changes in energy intensity associated with economic growth, shifts in best-observed performance, and country-level catch-up. Historical progress falls well short of the required pace.
