Whether or not an increase in meltwater, in response to climate warming, will accelerate the movement of ice sheets has been contentious. This is because while water lubricates the ice-bedrock interface, helping to speed up the ice flow over short time-scales (days to weeks), it also stimulates the development of efficient drainage.
Using three decades of satellite images for a 170-km land-terminating stretch of the western Greenland Ice Sheet, Andrew Tedstone et al. report in the journal Nature that more meltwater does not equate to faster ice sheet motion. Rather, despite a 50% increase in surface melting, ice motion decreased in their 8000km2 study region by about 12%.