In the “high emissions” scenario discussed in the paper, by 2070 the air in Antarctica has warmed by 3 degrees celsius. It’s windier, which has altered currents, and in the summer so much ice has melted that in some places there’s none left. Several ice shelves have collapsed and the Antarctic Ice Sheets are thinning and retreating. Because of this, sea level is rising a little less than an inch a year and in the longer term will rise tens of feet—though less than two feet of sea level rise is already costing more than $1 trillion per year because coastal cities are flooding.
At the same time, in this model, regulations protecting Antarctica have been allowed to lapse. Pressures from a global population of more than 10 billion people have contributed to resource exploitation of both minerals and fishing stocks. Species already trying to cope with unprecedented ocean acidification and Antarctica’s changing geography are also contending with unprecedented human incursions from increased tourism and exploitation. It’s a bleak picture.