Read here. The UN's IPCC is a political agency with the sole objective of producing anti-CO2, pseudo-science reports regarding global warming and climate change. It achieves this not by conducting its own experiments or research, but by collecting 3rd party alarmist research and advocacy papers from Climategate-type of scientists and green activist groups that favor the anti-CO2 agenda report.
This approach to a political "science" report has often ended up producing latrine-level science, such as the discredited 'hockey-stick' temperature chart and now infamous Himalayagate affair.
The IPCC's reporting on glaciers, in general, has been robustly wrong and a major factor has been an assessment based on a simple, yet spectacularly wrong, glacier hypothesis. Simply stated, the IPCC assumed that warmer temperatures would cause greater glacier ice melt, thus causing a positive self-lubrication feedback that results in a consistent, accelerated glacier movement towards open water. Sounds good except for the reality part - it doesn't work that way.
Previous glacier research had determined that Greenland's glacier flow exhibited a long-term decrease over 17 years of warming and increased melting. Sundal et al., using satellite technology, analyzed glacier movement to determine why the IPCC glacier hypothesis did not agree with the obviously contradictory empirical evidence.
"The six scientists determined that "although peak rates of ice speed-up are positively correlated with the degree of melting, mean summer flow rates are not, because glacier slow-down occurs, on average, when a critical run-off threshold of about 1.4 centimeters a day is exceeded." Thus, and "in contrast to the first half of summer, when flow is similar in all years," they found that "speed-up during the latter half is 62% (± 16%) less in warmer years," so that "in warmer years, the period of fast ice flow is three times shorter and, overall, summer ice flow is slower...conclude that "simulations of the Greenland ice-sheet flow under climate warming scenarios should account for the dynamic evolution of subglacial drainage," because "a simple model of basal lubrication alone misses key aspects of the ice sheet's response to climate warming,"" [Aud Venke Sundal, Andrew Shepherd, Peter Nienow, Edward Hanna, Steven Palmer, Philippe Huybrechts 2011: Nature]
Additional ice sheet/glacier, failed-predictions and peer-reviewed postings.