Check out this denier's letter to the editor:
Much fiction is behind rising sea levels alarm
It's time to put some facts into one of the global warming fictions. Rising sea levels associated with sea-ice melting seems to one of the obsessions of Al Gore and other alarmists. [...] I ask each of you, whether a Ph.D or an elementary school student, to conduct this simple experiment.
Fill a glass tumbler to about an inch below the top. Add a few ice cubes until the water level is very near the top. After the ice has melted, observe the new water level. It will the same as , or lower than the top of the glass.
Some such laws of nature cannot be dismissed by sensational rhetoric.
[name and address redacted]
Those who call man-made climate change 'fictitious' and its popularizers 'alarmists' should take more care to construct an adequate argument rather than parroting old talk-radio misinformation. This commenter repeated a reworded version of this 1992 claim from infamous infotainer Rush Limbaugh:
"Even if polar ice caps melted, there would be no rise in ocean levels... After all, if you have a glass of water with ice cubes in it, as the ice melts, it simply turns to liquid and the water level in the glass remains the same."
(The Way Things Aren't: Rush Limbaugh's Reign of Error, p. 17)
While this example appears sound at first glance, it fails spectacularly as an analogy. This is because the melting ice which concerns climatologists is on land--not floating in the oceans. The two largest and most obvious examples, the Antarctic Ice Sheet and the Greenland Ice Sheet, contain tens of millions of cubic kilometers of ice that lies above sea level. As the ice sheets calve and melt, sea levels will rise dramatically--just as the water level in a glass rises when one adds ice cubes to it.
Such laws of physics can be ignored by climate-change deniers, but cannot be dismissed as rhetorical.