The article assesses the future role of hydrogen-based iron and steel making and its potential impact on global material flows, based on a combination of technology assessment, material flow analysis, and microeconomic analysis. Renewable hydrogen-based iron production can become the least-cost supply option at a carbon dioxide (CO 2) price of around United States dollars (USD) 67 per tonne. Availability of low-cost renewable electricity is a precondition. Australia is the world's largest producer of iron ore and at the same time a country with significant low-cost renewable electricity potential. A shift to direct reduced iron (DRI) exports could reduce global CO 2 emissions substantially and at the same time increase value added in Australia, while maintaining steel production in countries that are currently processing ore into iron and steel, such as China, South Korea, and Japan. The approach could be expanded to other parts of the world and other energy-intensive industry sectors. Such relocation analysis in a climate context can become a new industrial ecology research area. Iron and steel industry CO 2 emissions can be reduced by nearly a third, around 0.7 gigatonnes (Gt) CO 2 per year. To achieve these emission reductions, investment of USD 0.9 trillion, or 0.7% of the total energy sector investment needs, would be required, global DRI production would have to increase seven-fold from today's level, and the hydrogen energy used would equal 1% of global primary energy supply. Such a shift could develop from 2025 onward at scale, if the right policies are put in place. K E Y W O R D S commodity trade, decarbonization, hydrogen, industrial ecology, iron and steel, renewable energy 1 INTRODUCTION 1.1 Industrial competitiveness in times of decarbonization policies The Paris Climate Agreement and the subsequent Special Report of the Intergovernmental Panel on Climate Change (IPCC, 2018) have created a new level of urgency that has prompted policy makers to revisit industrial greenhouse gas emissions. There is a renewed effort to find and deploy innovative solutions to decarbonize industry, a sector that has made limited progress to date. High costs have hampered action to date. Morfeldt, Nijs, and Silveira (2015) estimate a carbon dioxide (CO 2) price range of United States dollars (USD) 25-120 per tonne 1 for the blast furnace (BF)-CO 2 capture and storage (CCS) route to be globally cost competitive by 2050. Ruijven van et al. (2016)) estimate a CO 2 tax of USD 100 in 2020 rising to USD 324 per tonne by 2050 to reduce global iron and steel sector emissions by 80-90% compared to the 2010 level. Mousa, Wang, Riesbeck, and Larsson (2016) calculate a USD 50-200/t CO 2 tax for cost-competitive BF charcoal injection. Vercoulen et al. (2018) estimate a 70% reduction in East Asia iron and steel sector CO 2 emissions in 2050 with a CO 2 tax of USD 200/t. 1 All tonnes (t) refers to metric tons.