Also, wasn’t the 250 ppm atmospheric CO2 concentration prior to the start of the Industrial Revolution a historic low as far a geological-time goes?

I suppose that’s not particularly relevant for more recent old growth tall trees that seem to have got by fine in a colder Earth.

But it’s easy to imagine a warmer, wetter, Earth with higher atmospheric CO2 concentrations being more conducive to taller tree growth.

On the other hand, I probably don’t really know what I’m talking about, not my area of expertise.