Steel causes nearly a tenth of global emissions because coal is used to pull oxygen out of iron ore. Hydrogen can do the same job, leaving only water vapour, & when combined alongside electric furnaces powered by renewables it cuts emissions by more than 90%. Sweden's HYBRIT & Stegra projects, Germany's thyssenkrupp & Salzgitter conversions, & pilots across Asia are leading the way. Progress is slowed by expensive hydrogen & electricity, trade tariffs & weak steel markets, but the technology itself has been proven.