Quantifying the global energy transition: A policy-ready framework linking renewable deployment and emissions outcomes

This study introduces a new Energy Transition Index (ETI) model for quantifying the relationship between energy transition driven by policy and emissions outcomes. ETI is driven by Renewable-to-Fossil energy ratio (RE/FF), which when increased by 1.0 increases the ETI by 0.528 units (p < 0.001) and Policy Score. Energy Intensity (EI) modeling reveals that national recovery paths diverged post-COVID. In countries like Germany and France, where recovery aligned with climate goals, ETI grew by 2.2–3.6 % annually. In fossil-dependent nations like the USA and Mexico, recovery stalled or reversed. Investments in infrastructure had a dual effect: where electrification and grid modernization increased emissions intensity (+0.34 and + 0.47 coefficients respectively) unless accompanied by clean energy. Even with strong energy demand reductions, 2050 emissions are projected at 20–30 Gt CO 2 /year—well above the 1.5 °C target range of 5–10 Gt. This framework allows policymakers to run simulations of interventions, track their progress through benchmarking, and focus on those interventions that produce the most substantial impact—illustrated by a 60 % increase in RE/FF in Germany, resulting in a 50 % halving of emissions intensity from 2015 to 2022. Key recommendations are to coordinate the deployment of renewables, policy, and infrastructure construction; to leverage green stimulus finance; and to target climate finance toward institutional gaps. As a replicable tool for net-zero planning, the model could be improved by incorporating nonlinear policy effects and regional barriers. The findings show that closing the gap between climate pledges and action will require coordinated, data-driven, and systematic strategies. • New Energy Transition Index (ETI) model links policy to emissions outcomes. • RE/FF ratio and Policy Score are key drivers. • COVID-19 recovery strategies caused 2.2–3.6 % vs −1.6 % ETI growth divergence. • Infrastructure upgrades boost emissions intensity if not paired with clean energy. • 2050 simulations show 20–30 Gt CO 2 /yr even in best-case energy scenarios.