From the final page of the paper:
While continued increases in dynamic thinning are expected in response to thinning of adjacent ice shelves in WA1 and the AP (Cook and others, 2005; Pritchard and Vaughan, 2007; Rott and others, 2011; Shuman and others, 2011; Pritchard and others, 2012), the long-term dynamic thickening in EA and WA2 should provide a significant buffer against such continued increases in mass loss. If dynamic thinning continues to increase at the same rate of 4Gta^–2 with no offset from further increases in snowfall, the positive balance of the AIS will decrease from the recent 82Gta^–1 to zero in ~20 years. However, compensating increases in snowfall with climate warming may also be expected (Gregory and Huybrechts, 2006; Winkelmann and others, 2012).
In other words, we expect the rate of melting (dynamic thinning) is going to increase. It may be that snowfall is going to increase, but (unstated) the rate might not be high enough to compensate for the increased melting... (It "may be expected" but it also might not be.)
Cheers,
Scott.
NASA says Antarctica is actually gaining ice
