This expert-led webinar explores hydrogen-based steelmaking and its role in reducing emissions from primary iron and steel production. It compares blast furnace/basic oxygen furnace, electric arc furnace, and direct reduced iron routes, examining their raw materials, energy requirements, and carbon implications. The module analyses the thermodynamic consequences of replacing carbon with hydrogen as a reducing agent, including the transition from exothermic to endothermic reactions and the resulting reactor heat-balance requirements. It also examines the scale, cost, energy, and ore-quality constraints affecting green-hydrogen deployment. Complementary decarbonisation pathways—including molten oxide electrolysis, biochar and biomass substitution, and carbon capture and utilisation—are considered to support comparison of emerging options for lower-carbon steel production.