Whether the warming is effected by man is not something that we can directly determine with this study.
Climate warming can work in different ways, but generally speaking, if you warm up the ice sheet, the glacier will flow faster.
We are witnessing enormous changes, and it will take some time before we understand how it happened, although it is clearly a result of warming around the glaciers.
These findings call into question predictions of the future of Greenland in a warmer climate from computer models that do not include variations in glacier flow as a component of change. Actual changes will likely be much larger than predicted by these models.
This is clearly a result of warming around the periphery of Greenland.
In the future, as warming around Greenland progresses further north, we expect additional losses from northwest Greenland glaciers, which will then increase Greenland's contribution to sea level rise.