IIRC, IANAC, the context: Plants keep their leaf pores open to get CO2 inside the leaf for photosynthesis. On the other hand, they lose water if they keep them

IIRC, IANAC, the context: Plants keep their leaf pores open to get CO2 inside the leaf for photosynthesis. On the other hand, they lose water if they keep them open. With more CO2 in the atmosphere, they can keep the stomata a little bit more closed and grow the same with less water loss, meaning drier areas could get greener, droughts might not hurt so much etc. But now it seems this effect might have been overestimated.