An important point about plants is that they absorb CO2 through the pores in their skin.
If there is very little CO2 in the air, they must open their pores wider to catch it. However, in the process, they lose moisture through their pores. Conversely, if there is more CO2 than normal, their pores are narrower and they lose less moisture.
Moisture they uptake from the ground. So more CO2 in the air, means more moisture left in the ground, which means that more plants can live in the same ground.
On the grand scale, this can create “de-desertification”, meaning that plant life starts taking over land that was previously desert.
Plants can be powerful, en masse. When enough of them take over a place, the air above it cools, which in turn tends to increase precipitation.
Which means that a larger fraction is lost to ground-water. That is actually a drought inducing mechanism.