Don't have 20 mins to read through but I get the gist. The main argument I'm seeing is that raising atmospheric carbon levels is still problematic. That's true, but I think the article is neglecting the source of the carbon emissions and why that matters.

Coal is a fossil fuel. Those hydrocarbons are trapped underground and have no realistic way of coming to surface in a human timescale. In essence, burning coal and releasing a ton of CO2 is adding carbon to the cycle that was never there before.

Compare that to biomass. Biomass collects carbon from the atmosphere. This is why planting trees is seen as green, a ton of dry biomass is about a ton of carbon removed from the atmosphere. When that biomass is burned, or decays, it will release CO2 back into the atmosphere, continuing the carbon cycle. Yes, that will raise atmospheric CO2, but it doesn't raise the net amount of carbon in the cycle. That's why it's called carbon neutral. Neutral isn't green, and it doesn't have to be. It just has to reduce the amount of new carbon entering the system