True or not, seems weird to dump poison in the atmosphere - why not err on the side of clean air?
CO2 is not a poison.
Anything is a poison in the right doses, but what about carbon monoxide, sulfur dioxide, methane, etc.?
It is interesting to note that normal concentration of CO2 in the blood of mammals is higher than that in the atmosphere. It means that in ancient times the atmospheric concentrations of CO2 were much higher than now. So, by burning coal, we just return carbon to the atmosphere that was previously taken by plants...