Greening is talked about Michael, extensively if you look.
Yes there is greening happening and a large part of that is due to carbon fertilisation. The two countries that account for the majority of the area of greening equivalent to that of mainland USA are China and India. Both of those countries introduced specific measures to increase forests etc in an effort to help clean their air. Also some of that greening comes from increased crop planting in both those countries (nitrogen).
Despite all the greening that has already happened CO2 in the atmosphere is still increasing and emissions are increasing still. The greening isn’t able to keep up with the amount of CO2 emitted.
Also, apparently plants acclimatise to the extra CO2 and the greening diminishes over time.