Well with cheap carbon free electricity, we could cut all the CO2 emissions from iron and steel with hydrogen based reduction and about half that of cement manu

Well with cheap carbon free electricity, we could cut all the CO2 emissions from iron and steel with hydrogen based reduction and about half that of cement manufacture (about half the carbon use is energy cost for heating as per Wikipedia article). Together about 15% of global emissions could be eliminated which is nothing to sneeze at. In fact many intractable problems in the world can be solved by more clean electricity - eg. 8000 odd skyscraper farms are enough to feed the world eliminating farm-land requirements but would require enormous amount of energy to run - also would represent single points if failure to attack in war - so will need society to evolve