I realise this is a silly thought experiment but the point of comparison should be, at the very most, the human industry generated CO2, not all natural CO2. The CO2 from this particular process is probably more relevant and since this process generated 1 ton of Cl per ton of Steel and the normal process generated 3 tons of CO2, we should give it a 66% discount.
> I realise this is a silly thought experiment but the point of comparison should be, at the very most, the human industry generated CO2, not all natural CO2
The pre-industrial levels of CO2 were around 280ppm, while the current CO2 levels are around 440ppm.
For Cl2, in occupational-health situations the permissible exposure is around 1ppm per hour, or 3ppm for 15 minutes. So the 160ppm we'd throw into the atmosphere in this thought experiment (or even the 52ppm at the suggested discount) is going to cause some pretty big problems pretty rapidly.
