The key problem is that, as the article highlights, iron is widely available and its energetic cost per ton is relatively small. This means that we actually need to reduce steel production, not just replace it with something else and call it a day. Doing the later would cause more harm than good.
For that, I think that consistent application of the three R's (reduce, reuse, recycle - in this order, and stop forgetting the first two R's dammit) would be a good start. And perhaps legislative measures against businesses trying to prevent you from applying the three R's.
In the meantime, perhaps look for alternative steel productiion processes? You need some carbon as it's part of the alloy, but I wonder if the bulk of the reduction could be done by electricity instead. And even the carbon could be sourced from renewable sources; more expensive, but doable.