I've been wondering about this for a while, but haven't looked into it
https://www.sciencealert.com/here-s-why-plants-don-t-just-grow-faster-with-more-carbon-dioxide
For example
QuoteThe effect of CO2 on the amount of water plants use may be more important than the primary effect on photosynthesis. Plants tend to close their leaf pores slightly under elevated levels of CO2, leading to water savings.
But they are cautious to say that we still don't know exactly how plants will react given the magnitude of the change
QuoteA tree planted in the 1850s will have seen its diet (in terms of atmospheric carbon dioxide) double from its early days to the middle of our century.