"The largest glacier in the world is the Lambert-Fisher Glacier in Antarctica. At 400 kilometers (250 miles) long, and up to 100 kilometers (60 miles) wide, this ice stream alone drains about 8 percent of the Antarctic Ice Sheet." This glacier is 1/375 of the earth's total ice cover. If it were the average thickness of the earth's ice cover, then sea levels would rise 230/375, or 0.61 feet, or 7.36 inches. Since thicker ice depths would be thicker in the interior, and coastal ice depths would be less, 4 or 5 inches would be an approximate increase from this one glacier alone.
I suspect that the alarmist author divided the average glacier depth of 5,520 by 375, which gives 14.72 feet. Adjusting this down some for thinner coastal ice depth would give about 10 feet.
It's worth noting that if the 230 feet figure is correct, raising oceans 10 feet would require that about 4.5% of the ice pack melts. However, I personally believe Proverbs 8:29 "...He assigned to the sea its limit, so that the waters would not transgress His command." Thus, we find like all things liberal, the root is despising God and His word.
“Glaciers and ice cover are about 15,000,000 square kilometers”
Covering, what, exactly? Land or water?
Glaciers melting over water would NOT contribute to rising seas but actually to the lowering of the seas by 10% of the glacier size.