It has almost been three years since I sent this question over to John Cook’s Rapid Response Team. I expect to hear from them any day now.
Antarctic sea ice is currently about three standard deviations above normal, according to NSIDC graphs.
The excess sea ice is necessarily located at relatively low latitudes, and the sun is near its peak in Antarctica now. This means that large amounts of sunshine are being reflected back into space by the excess ice.
How much southern hemisphere cooling does this excess ice generate?