Maybe there is a much simpler explanation for the rise of seawater of which you talk ? http://www.natureworldnews.com/articles/7560/20140613/vast-underwater-ocean-trapped-beneath-earths-crust.htm. If the water known now to be beneath the earths crust had pressure exerted from below due to magma expansion this would drive this water, 3 times the volume of our present oceans up and changinging the water height !1 So you see that its not necessarily this " global warming " that you state but more alot more water being pumped up from below !! I personally think this has happened before and could be the explanation for the great flood recounted in the bible at the time of Noah !!