https://www.skepticalscience.com/Greenland-ice-mass-loss-spread-to-northwest.html
https://www.agu.org/pubs/crossref/2010/2010GL042460.shtml
https://news.discovery.com/earth/more-greenland-ice-melting-faster.html
https://www.skepticalscience.com/What-CO2-level-would-cause-Greenland-ice-sheet-collapse.html
https://www.the-cryosphere-discuss.net/4/233/2010/tcd-4-233-2010.html
“…Collapse of the ice-sheet was found to occur between 400 and 560 ppmv…”