'Their new survey covers just three years, up to 2013. The previous period, that they compare against, was 2005-11. Would any serious scientists use such short periods to make claims about trends?'
It has been widely reported that “the Antarctic is shedding twice the amount of a few years ago”. I have picked out the Guardian, but the BBC run with the same story, and doubtlessly many others too. Quite simply, the claim is false. The study finds that the new figure is “twice as much as when it was last surveyed”. These are two totally different things. The new Cryosat-2 radar altimeter dataset allows much more detailed analysis, leading to a fivefold increase in the sampling of coastal regions where the vast majority of all ice losses occur. Therefore, most of the newly identified ice loss was happening before, but just was not spotted.
Of the figures they quote, by far the largest area, East Antarctica, is only losing 3Gt/year. Given that the margin of error is stated as +/-36, this is effectively zero, and it is quite likely that ice mass is growing there.
We need to put these findings into historical perspective. Antarctic land ice has been steadily disappearing since the end of the Ice Age, some 18,000 years ago.
Studies show that Antarctic temperatures during the MWP and earlier centuries were comparable with or higher than present.
It is claimed that the current ice loss in the Antarctic is enough to raise global sea levels by 0.45 millimetres each year, but much of this rise has already been occurring throughout the last century. As there has been no noticeable change in the rate of sea level rise since 2010, there is no evidence that the new figures claimed for Antarctica represent any significant increase...over a century an extra 9mm of sea level rise. Hardly apocalyptic!!'