"Steel can be made carbon free, but so far it's all made in a blast furnace with a lot of coal." Most (think I'd heard 75-80%) of it is made in electric arc fu

"Steel can be made carbon free, but so far it's all made in a blast furnace with a lot of coal." Most (think I'd heard 75-80%) of it is made in electric arc furnaces from scrap steel these days. This is a big factor in the Rust Belt's decline and Nucor's (and China's) advance: we made enough steel that now we have surplus scrap, and it's cheaper to melt it down and reform it than to dig more iron ore out of the ground and make steel in blast furnaces. I thought aluminum production was also largely in electric arc furnaces, and the main CO2 contribution was generating the electricity used for it. Edit: apparently it's about 70% of steel in the U.S. is produced by electric arc furnaces, and they produce about 85% less CO2 than blast furnaces. Aluminum is produced in electric arc furnaces, but with carbon electrodes, which release about 1/2 lb of CO2 for every pound of aluminum.