Even if the world is warm enough to melt the sheet completely, that would take centuries, if not millennia; Greenland's ice is thousands of meters thick. In a bad scenario, the IPCC forecasts 21st century sea level rise to be a bit under a meter (https://www.climatecentral.org/news/zeroing-in-on-ipccs-sea-...). This will certainly cause problems, but is nothing like the complete and rapid destruction some pundits describe.
Major action on carbon emissions is long overdue, and it's great that people are taking it more seriously now. But an overly-pessimistic scenario has the same problems as an overly-rosy scenario; if we're all doomed anyway, why do anything? Michael Mann, the climate scientist who famously brought global warming to public attention, now also spends time fighting doom scenarios which also discourage action:
Major action on carbon emissions is long overdue, and it's great that people are taking it more seriously now. But an overly-pessimistic scenario has the same problems as an overly-rosy scenario; if we're all doomed anyway, why do anything? Michael Mann, the climate scientist who famously brought global warming to public attention, now also spends time fighting doom scenarios which also discourage action:
https://alumni.berkeley.edu/california-magazine/summer-2020/...