What was done
The authors used spatially-dense estimates of ice-flow velocity obtained from synthetic aperture radar to assess the mass balance of the Ross Ice Streams of West Antarctica.

What was learned
In the words of the authors, their results indicate that "contrary to earlier estimates, the mass balance of this sector of the West Antarctic Ice Sheet is positive."  Instead of a previously assumed ice mass deficit of 20.9 gigatons per year, they found evidence for an ice mass accumulation of 26.8 gigatons per year.  This build-up of ice was not the result of climate-driven changes in ice accumulation or melt, but was rather a consequence of internal ice stream dynamics, which seem to be slowing the flow rates of many of the ice streams.  Ice Streams A and B, for example, have been decelerating at an average rate of 5 meters/year every year since 1974; while Ice Stream C completely stagnated fully 150 years ago and has been growing thicker ever since.

What it means
In the words of the authors, "the positive imbalance we observe and the trend toward a potentially larger imbalance are evocative of an ice sheet in advance rather than in retreat."  Such an observation, if it continues to hold true, would be dramatic indeed; for the West Antarctic ice sheet has been retreating for several thousand years.  Hence, as the scientists say, "if the current positive imbalance is not merely a part of decadal- or century-scale fluctuations, it represents a reversal of the long-term Holocene retreat."

It is interesting to note, in this regard, that the prior several-thousand-year retreat of the West Antarctic ice sheet is indisputably of natural origin.  But what about its recent possible turn-around to a state of advance?  If the order of these events had been reversed, i.e., if there had been a several-thousand-year advance of the West Antarctic ice sheet followed by a possible transition to retreat, you can bet your bottom dollar (or euro) that the climate alarmists of the world would be angrily jumping up and down doing everything imaginable to condemn the burning of fossil fuels for the new threat this CO2-emitting activity posed to the world's low-lying islands and continental coasts, which behavior would indeed have a modicum of reasonableness associated with it.  To do so now, however, in the face of the absolute opposite course of history, is an abject denial of physical reality.  Yet climate alarmists will continue to do just that; for it is one of the defining characteristics of this rare breed of bird that reality just doesn't cut it, especially when it comes to getting the people of the world to submit themselves to the will of a self-anointed group of seers who knows, far better than we, what's best for us.