Higher humidity... More rain?

Increased CO2 in our atmosphere essentially humidifies the air. As the planet warms with climate change, the atmospheric water vapor increases by as much as 6.5 percent per degree Celsius, according to recent satellite data. More water vapor could mean more rainfall, though current climate models predict that evaporation will increase slowly and rainfall will hardly rise at all. See Planning a Picnic in a Warming World? Satellite Forecasts More Rain.