Two Planet Steel is starting to make special steel, called clean-steel.
Clean-steel is made using renewable energy with zero carbon dioxide (CO2) emissions.
We now have a NASA contract to develop technology for small-scale, clean-steel production on Mars (it is small so that it can fit inside small Mars landing craft). However, this technology can be implemented on Earth on small, intermediate, large and very large scales.
A single clean-steel production facility can be made using batteries of small modules, so that it can start small and then easily grow larger with the addition of more modules. This means a new clean-steel production facility can start with small capital outlays. Two Planet Steel will plow profits back into plant to increase steel production. This is a recipe for exponential early growth with rapid (short) production doubling times. Two Planet Steel expects doubling times to be very short early on, as it will concentrate on making highly profitable clean-steel art and design works for the home (for customers willing to support the spread of clean-steel for the benefit of Earth), and also highly profitable, expensive steel powder for use in 3D metal powder printers.
The transition from blast furnace iron ore smelting to clean steel production, applied globally, will be a huge benefit. In 2015 iron ore smelting blast furnaces emitted about 2.0 billion tonnes of fossil fuel sourced CO2 into Earth's atmosphere. That is 6% of all the 2015 CO2 emissions by all fossil fuel and forest burning done everywhere on the planet. Globally, blast furnace iron ore smelting is at the top of the list of fossil fuel CO2 emitters along with burning fossil fuel for transportation, burning coal and natural gas for electricity production, and cement production.
Clean-steel will quickly become profitable and then a global benefit.