Nah, there's wind, and the ocean. Less humid air evaporates ocean water quicker, and the wind will circulate the air till it eventually reaches the ocean.

The Earth is enormous, it would take a staggering number of these to make any dent in humidity, and even then it would be a local dent only.

Don't forget water is a closed loop - this water they consume is also eventually returned to the environment (sweat, etc.), where it evaporates and restores the humidity.