An interesting trivia bit is that when plants inhale CO2 through pores in their leaves, they also lose moisture from their pores, moisture which they have brought up from the soil.
However, when there is a greater concentration of CO2 in the air, they don’t have to open their pores as wide, so lose less moisture, so draw less moisture from the soil.
This matters a lot in places with deserts, because the more moisture in the soil, the more plants it can support. And the plants also help fix the moisture in the soil.
So with greater CO2, deserts will start to shrink, which also has a cooling effect on the air above them, that may contribute to more precipitation.
Importantly, about 300 million years ago, most of the Middle East was wet jungle, more like the Amazon River Valley is today.
IIRC, the formation of the Himalayas when the island that was the Indian subcontinent collided with the Eurasian landmass was what cut off the flow of moist air that had previously flowed over the Sahara and MidEast, and forced it to take a more southerly route. Thus the drying out of North Africa and the MidEast.