Is the lumber increasing from increased CO2 alone? I somehow thought that forest balancing had more factors, - the vital ones being re-planting, and even temperature....
For the global stock is decreasing.
I am well aware that if you whiff up the CO2, plants will respond by harnessing more carbon, thereby growing better, - especially on a certain level. We use this in agriculture, - in the GREENHOUSE business
Over where I live, the air is clear, and less ppm C than down on mainland Europe. But when we get the winds from the UK and mainland Europe, there is no need for adding CO2 no more...
As for the crops responding, they will also respond to increased temperature and droughts. The hottest areas will become less bearable, while cooler areas become...nicer. But the landmass on the hotter areas is more, so with GW carrying on, crops will eventually drop as a total.
Some of the really high crop areas today, where a lot of Earths stock of food is made, do not take a lot of heating...