One month ago, I arrived with a team of scientists at Elephant Island, Antarctica—a lonesome, 29-mile-long hunk of glacier and granite off the tip of the Antarctic Peninsula. The island was chronicled by a member of Ernest Shackleton’s ill-fated 1916 expedition as “about as inhospitable as one could well imagine,” and it hasn’t changed much in the past century. Even today, some of its coastlines have been explored by fewer people than have stepped foot on the moon. We came to the end of the Earth with a specific purpose: to see how Chinstrap Penguins are coping with a shifting environment. Climate change has hit the Antarctic Peninsula hard in the past half century, with mean annual temperatures up by several degrees. Just last week, an Argentinian research station 160 miles south of Elephant Island recorded an air temperature of 64.9 degrees Fahrenheit, the hottest ever measured in Antarctica. We suspected that warmer conditions are causing cascading impacts on ice...