This is either a joke or you don't know how your tools are made. I'm hoping it's the former.
The carbon in the steel serves two purposes. One, it alters the structure of the final steel. Too much, or too little and the metal doesn't behave right, so it's not fit for purpose. Two, it's a sacrificial reducer that keeps any stray oxygen from eating the metal during the heat and cool cycles (most of us call hot oxidation 'burning').
You're still going to need a little carbon to get the steel right and maybe to help catch a few stray oxygen atoms, but if you can heat the metal with something other than coal/charcoal, and you can provide another reducing agent, then you don't have to bathe the entire process in carbon. You'd just need enough to get the crystalline structure right, and perhaps a margin of error. And that sort of fraction could come from renewable resources.
