drilled ice cores up to deep. Scientists have, using those ice cores, obtained information on (proxies for) temperature, ocean volume, precipitation, chemistry and gas composition of the lower atmosphere, volcanic eruptions, solar variability, sea-surface productivity, desert extent and forest fires. Subglacial sediment from ~ beneath the ice stored since 1966 indicates that Greenland was completely ice-free and vegetated at least once within the last million years. This was not expected and may show Greenland to be more fragile and sensitive to climate change than previously thought. Recent climate change General considerations on rate of change In the earlier decades, an area in the North Atlantic including southern Greenland was one of the only areas in the World showing cooling rather than warming, and Greenland had shown more complex temperature trends than the other areas of the world. A 2006 paper on Greenland's temperature record showed that the warmest year on record was 1941 while the warmest decades were the 1930s and 1940s. The data used was from stations on the south and west coasts, most of which did not operate continuously the entire study period. However, later and more complete data sets have established strong warming in the period 1979–2005 (consistent with the concurrently observed Arctic sea ice decline and its ice-albedo feedback) As the Greenland Ice Sheet had experienced unprecedented melting since the detailed records began, and is likely to contribute substantially to sea level rise as well as to possible changes in ocean circulation in the future. Several factors determine the net rate of growth or decline. These are: Accumulation and melting rates of snow in the central parts Melting of surface snow and ice which then flows into moulins, falls and flows to bedrock, lubricates the base of glaciers, and affects the speed of glacial motion. This flow is implicated in accelerating the speed of glaciers and thus the rate of glacial calving. Melting of ice along the sheet's margins (runoff) and basal hydrology, Iceberg calving into the sea from outlet glaciers also along the sheet's edges The last time that the combination of these factors had resulted in a net mass gain was in 1996. As of 2022, Greenland ice sheet had been losing ice for 26 years in a row. The snow line is the dividing line between the area, above the snow line, where snow continues to accumulate during the summer, and the area