[Dylan16807]

You are vastly overestimating the efficiency of turning life into oil, and vastly overestimating how much has gone into steel. The article even addresses the energy needed to reduce iron, and it's not that much. The high number of 60kJ/mole/reduction comes out at about 500 food calories per kg to reduce twice. Industrial molten iron production is only around 5000 food calories per kg. So it's really no big deal to produce a few kilograms per lifetime. (Mixing in other elements to get steel is a minor cost per kg.)