Better unplug your phone charger, or a 2,000-meter-thick chunk of ice the size of Mexico may become "too light to stand firm"

Erik Rasmussen: The World's Most Dangerous Doubt

...a complete meltdown of the entire Antarctic ice sheet would cause an increase in the global sea level of 61.1 meters.

Although the timeframe for this kind of sea level rise, in most reports, is very long, new studies suggest, that a tipping point, which can lead to great and irreversible rise in global sea level, may not be so far away. Today, the west Antarctic ice sheet stands firmly on the seabed. But if temperature rises, and parts of the ice sheet melt, there is a risk that the remaining ice cap becomes to light to stand firm. This will mean that water will flow under the ice cap and thus possibly tear it loose. If this happens, the West Antarctic ice sheet will be a huge iceberg flowing out to sea. It will cause a 5 meters increase in global sea level.

West Antarctic Ice Sheet May Be A Smaller Source Of Current Sea-Level Rise

ScienceDaily (Dec. 28, 2000) — The West Antarctic Ice Sheet’s contribution to global sea-level rise may be much slower today than it was in the past. New evidence indicates that the size of the ice sheet thousands of years ago has been overestimated and the ice sheet may not have been as big or as steady a source of sea-level rise as scientists thought.
...Currently, the ice sheet averages 2000 meters thick, covers an area the size of Mexico, and contains enough water to raise global sea level 5 meters.