Why doesn the movie mention anything about the sea ice in Antarctica?
WALT: The Antarctic sea ice is not showing the dramatic downward trend that we are seeing in the Arctic. There are a couple reasons for this. First, the circulation of the atmosphere and oceans isolates the ice-covered ocean around Antarctica, keeping things colder. So, global warming effects have not yet been pronounced there. And, unlike the sea ice in the Arctic, much of which stays around the entire year, most of the sea ice in the Antarctic already melts away during the summer so any summer warming would not have as much of an impact. However, sea ice around Antarctica plays a key role in ocean circulation by producing dense cold water that sinks to the ocean floor and helps drive the ocean’s “conveyor belt” circulation. Sea ice is also key to biology in the region, which is one of the most productive marine environments in the world. There already have been some changes noted in the timing of when the sea ice forms and melts around the Antarctic Peninsula, which has shown signifi
