You're not telling me something I don't know, LeGrande. In fact, if you want to read a bit more, read this article and thread:
Deciphering Contradictory Antarctic Climate Patterns
particularly: "Counterintuitively, global warming would actually lower sea levels at first. In warmer temperatures, evaporation of ocean water increases and more snow falls, more than offsetting the melting ice at the edges. But over the longer term perhaps centuries, perhaps thousands of years prolonged warmth in Antarctica would add to the ocean depths."
which you noted. There are also other factors, such as the thermal expansion of seawater, which could offset a lowering due to increased precipitation, (and impoundment of fresh water in reservoirs). So sea level is not a great proxy measurement by which to confirm or deny global warming.
So my proposal to Cogitator is this. I have a place down in Baja on the ocean where I can measure the surface level very accurately. I have access to all kinds of instruments, I have a GPS laser level and some other nifty stuff (I can accurately measure down to a millimeter). So if you can tell me how to do that I would be very appreciative.
First of all, Baja California and southern California are not great places to do this unless you have a stable offshore platform. Why? Tectonic activity. The Northridge earthquake raised the mountains by Los Angeles 3-4 cm. The San Andreas fault runs through your backyard, doesn't it? When determining sea level rise/fall, you have to remove all the other local phenomena.
I know that what I am asking is not very straight forward when you have to take into consideration the position of the sun and the moon, wind, waves, currents, temperature, barometric pressure, etc. But I do know that compared to predicting the weather, determining the oceans level is child's play. It also seems that some of the predictions of several meters in the next 50 years would be easy to see now, they would be close to a centimeter a month.
Well, if you do it with a method like satellite laser altimetry and take into consideration all of the +/- factors, you get something like this:
I will collect the data over a period of time (I like to go fishing and snorkeling) and then it should be very easy to prove or disprove the validity of global warming and even state how accurate it is. :)
I think that more than one data point is necessary to make a respectable evaluation.
Are you up to the challenge Cogitator?
Usually.