New York Times: With their boundless vistas of turquoise water framed by swaying coconut palms, the Carteret Islands northeast of the Papua New Guinea mainland might seem the idyllic spot to be a castaway. But sea levels have risen so much that during the annual king tide season, November to March, the roiling ocean blocks the view from one island to the next, and residents stash their possessions in fishing nets strung between the palm trees. "It gives you the scary feeling that you don’t …