Decarbonization pathways and mitigation potential assessment for the steel sector in Southeast Asia

Abstract Southeast Asia’s steel sector faces the dual challenge of expanding production to meet rising demand while reducing carbon emissions. This study develops a bottom-up cost minimization model with 19 steelmaking technologies for six Southeast Asian countries over 2020–2070 and applies a three-dimensional scenario design that varies carbon pricing, technology cooperation, and infrastructure readiness at two levels each, yielding nine scenarios including a business-as-usual scenario (SC0). Rather than treating the three dimensions as strictly independent, we use the design to diagnose how they interact along a combined axis of policy ambition. Without climate policy, BF-BOF expansion locks in rising emission intensity, reaching 1.14 tCO 2 /t by 2040, 18% above the 2020 level. Under the most favorable policy combination, emissions fall by 67% from SC0 by 2050. Carbon pricing contribu…