Note also that the winds are driven by the temperature difference between the equator and the poles.

The greenhouse effect warms the poles more than it warms the equator, thereby lowering that difference. So less wind. Which means the water that evaporates and then precipitates back down spends less time traveling horizontally in the wind. Evaporate straight up. Fall straight down.

So, wet areas get wetter. Dry areas get dryer.