Read here. Al Gore and other prominent alarmists have relied on computer model predictions, which allowed them to make incredible claims of sea level rise due to major ice sheets melting. A new peer-reviewed study finds that the ice sheet models significantly overestimated ice-mass loss, and as a result, the projected maximum IPCC sea level predicted rise is no longer credible.
"We don't really have an ice-sheet model that we trust,"
It's another case of prediction failure by computer models:
"Assessments of the glacial isostatic adjustment typically rely on deglaciation models—which simulate the evolution of the ice sheets since the Last Glacial Maximum—together with assumptions about the viscosity profile of the mantle. Much is still unknown regarding the history of the ice sheets, and even less is known about the behaviour of the mantle in response to loading and unloading."
"Bottom line on the new work is that ice-mass loss has been overestimated by previous studies. “These findings confirm the ongoing shrinkage of the polar ice sheets,” state Bromwich and Nicolas. “However, and most importantly, the newly estimated ice-sheet mass losses represent less than half of other recent GRACE-based estimates for the same time interval: −230 ± 33 Gt yr−1 for Greenland2 and −132 ± 26 Gt yr−1 for West Antarctica.” According to Wu et al. “We conclude that a significant revision of the present estimates of glacial isostatic adjustments and land–ocean water exchange is required.”.....So, when the more exact measurement separation methodology of Wu et al. is applied to the GRACE geoid data, ice sheet shrinkage, which has been systematically overestimated, is cut in half. “The differences between the work by Wu and colleagues and earlier studies may reflect errors in present deglaciation models with respect to the ice-load history and response of the Earth's mantle,” conclude Bromwich and Nicolas. According to Wu et al. “significant revision” is required. The general result—the Greenland and Antarctica ice sheets will be with us for a long time to come."
