An increase in air temperature leads to an increase in evaporation as warmer air is able to hold more moisture. Incredibly, this means that since 1950, there is more moisture in the atmosphere to the tune of about 2 kg or 2 litres per every square metre of earth's surface. The total volume of water that has been evaporated is equivalent to twice the volume of Lake Erie - in other words, climate change has essentially boiled off Lake Erie twice over.
What does this mean? This means that when it rains - there is a lot more water that can come down.
This also means more humid summers and more likelihood of increasing heat index above danger levels. A particularly concern point is when the wet-bulb temperature rises above [TBD] degrees, which is the point at which we will not be able to maintain our temperature by sweating.