Here's an excerpt from Wikipedia:
The dew point is the temperature at which the water vapor in air at constant barometric pressure condenses into liquid water at the same rate at which it evaporates. At temperatures below the dew point, water will leave the air. The condensed water is called dew when it forms on a solid surface.Dew Point is important to consider because changes in the atmosphere over time may determine how much water can be suspended in the air. Ice doesn't just melt into liquid and raise the water level, water also evaporates into the air, but nobody seems to be discussing this. Over the last several decades we have introduced other particles and chemicals into the atmosphere that may enhance humidity.
Under current conditions, what is the maximum possible water volume that can be suspended in the atmosphere at the average global temperature? What was the average global temperature ten years ago and what was its water volume potential at that time?
Since we don't see humidity until it becomes dense enough to form clouds or fog, we don't think much about it. Most of the media has been reporting for years about how long it will take for the sea level to rise enough to flood major cities, but I never seem to hear reports on the density of water vapor in the atmosphere responsible for increasing the severity of hurricanes, tornadoes, flash-floods, blizzards, and the "Arctic Vortex" driving extremely severe cold weather into subtropical regions everywhere.
The Earth Observatory at NASA compares water vapor with other substances in the atmosphere over time. Climate.gov has a detailed page on Humidity. The Storm Prediction Center at the National Oceanographic and Atmospheric Administration's website (NOAA) has tons of raw data for research.
Given recent weather events it seems the atmosphere's capacity to hold water and conduct thermal energy is long overdue for public scrutiny. Instead, the main-stream corporate media prefers to leave its audience with the assumption that "It won't happen in my lifetime, what do I care?"