The limits of energy conservation: Why doubling current energy efficiency progress is no easy feat

Abstract

Energy efficiency is central to achieving global decarbonization objectives. The COP28 agreement calls for doubling the average annual rate of energy efficiency improvements from 2 % to 4 % annually by 2030. To explore the feasibility of this target, we first apply a Kaya-identity decomposition—at both global and regional levels—to separate activity, structural, and intensity effects, distinguishing conversion from final-energy efficiency at the point of use. The regional breakdown exposes marked heterogeneity across industrialized, emerging, and least-developed economies. We then used a complementary forecasting framework—autoregressive integrated moving-average, exponential smoothing, and prophet models—that provides complementary outlooks. While historical gains have moderated energy demand, sustained improvements beyond 2 % per year have been rare and typically driven by economic contractions rather than structural shifts. Our baseline projections reach only 1.9 % per year under current policies, leaving a persistent annual shortfall of 2–3 percentage points and a cumulative gap of ≈19 % by 2030. We interpret these findings through the multi-level perspective: (i) at the landscape level, international commitments outpace many national capabilities; (ii) at the regime level, established rules, limited finance, and “low-hanging-fruit” depletion slow further progress; and (iii) at the niche level, innovations such as widespread electrification, smart demand response, and low-cost retrofits can accelerate savings but remain unevenly accessible. Meeting the 4 % target will require binding performance standards, sizable financial incentives, accelerated technology diffusion, and explicit safeguards for affordability and equity.