I do understand what they're trying to say, which is a lot more sound than the whole rabbit cage and cinder block experiment. As I'm sure anyone who understands basic science knows (Admittedly that excludes a high percentage of DUmmies), you could melt all the floating ice in the world and it wouldn't change the ocean level, it is only the Antarctic continental ice shield, and Greenland's, that represent very large amounts of ice that rest on land and do not already displace an equal weight of oceanic water.
Global climate alarmists make a lot of noise about thinning of these two ice shields and a hidden pooling of meltwater under them in places that is supposedly a catastrophe in the making, however there is virtually no historical data upon which to base a trend line on either one. Prior to using satellites for detailed radar surveys of surface heights (And even more recently, trying to directly measure the ice thickness with more advanced systems), which has only been happening for around three decades, so the value of the alleged 'Settled science' is really pretty sketchy.