Bruce,

While you are correct that water vapor is a constant value as part of the totality, you are incorrect about vapor's position as a global warming factor. It is commonly accepted as the #3 factor.

Part of the problem is that the oceans are becoming fresher. Another part of the problem is that we, by development, are interfering with
the water cycle, in that we are paving over land and not allowing the water to seep into ground to replenish aquifers. By the same token, we are paving wetlands and interfering with purification. All of this means that we are wasting a replenishable resource.

We are working on establishing Atmospheric Water Generation [AWG] as the technology of choice. Unlike other technologies, AWG only needs the ambient temperature to be greater than 40 degrees F in order to extract usable amounts of water. The technology can be used for disaster relief as the largest "portable" machines can produce 60,000 gallons per day at 90 F and 90% relative humidity.

A secondary advantage of AWG [primary in terms of this discussion] is that, as you remove water from the atmosphere, more evaporates from the oceans, seas and large lakes. This allows a rise in salinity as the fresh water is applied to various human uses, such as providing water where there is insufficient clean water for consumption and agriculture. It also has the potential to ease uncomfortable high humidity during the warm months.

One of our goals is to produce sufficient high quality equipment to relieve droughts, refill aquifers and, eventually, push deserts back. In the case of Florida, for example, the aquifer has been so depleted that the limestone beneath a large part of the state has become dehydrated and lost strength. This allows sink holes to form. The best way to resolve this problem is to replace the missing clean water with clean water. The rate of natural replenishment is too low and, in many coastal areas or areas unserved by sewers, there is a good chance of toxic infiltration because of a lack of relative pressure from the aquifer.   

It is impossible to do only one thing. By improving quality of life we can also relieve Global Warming and relieve a source of political conflict.