Jim,
This quote makes it sound like the cooler mean sea surface temperatures around Antarctica will decrease projected future snowfall on the continent (I assume because the cooler sea surface water will give off less evaporation), thus resulting in higher projected increases in the rate of SLR. Furthermore, it sounds like the greater sea ice extent will insulate the warm CDW thus leading to more ice shelf and ice sheet melting; which will cool the sea surface even more. This will be an interest feedback mechanism to watch.