re: Measured sea-level is rising.
Excerpt from the site you directed to:
Douglas [1992] carried out a systematic global analysis of sea level acceleration, and arrived at a similar result that no acceleration of global sea level has occurred over the last 150 years that is statistically significantly different from zero at the 95 authors have bounded any acceleration that might have occurred in the last 150 years at an order of magnitude or more less than that predicted to accompany global warming in the future [ Houghton et al., 1990].
It seems that there is still a lot of controversy regarding the global changes.
The currently accepted (I'll call it your theory) postulates that the IR absorbing gasses in the atmosphere will prevent the IR radiation from escaping to space and that will cause a global warming, the global warming then will melt the polar ice and increase the sea levels.
But what if after many years of monitoring, we will see that the polar ice disappears, yet the sea levels are not rising according to predictions.
How would you explain such a situation?
In the end, it does not matter what you or I think is happening, what matters is what actually is happening.
On a related idea, can you tell me what happened to the water on planet Mars?