How can you explain an IF? It doesn’t work, the science says what it says.
Do you want someone to pump up the CO2 to 8,000 ppm like it has been in the past? I think it was actually closer to 13,000 ppm at times. In the depths of the ice age, it was down to 150 ppm. Plant life just about went extinct at that. It thrives at high levels of Carbon, it is toxic to life when at its lowest.
The “science” in the article is irrelevant to the greenhouse gas discussion. I don’t care about greenhouse gases, but the article has has nothing to do with the discussion. It is like discussing carburetors on a fuel injection car.