In January 2020, a hardy crew of environmental activists and penguin scientists – including me – took a ship from Argentina straight south, across the infamous Drake Passage, to an Antarctic outpost called Elephant Island.

I’d seized a rare opportunity, for my graduate research at Stony Brook University, to visit the island’s far-flung penguin colonies. As part of its Protect the Oceans campaign, Greenpeace International hosted our team of scientists on its ice-class research ship, the M/Y Esperanza. Powered by a hybrid electric engine and excellent vegetarian food, we set off to study penguins in places most other expeditions couldn’t go.

If Elephant Island rings a bell, it’s because it played a fleeting role in a desperate episode of Antarctic history. About a century ago, polar explorer Ernest Shackleton washed up here with 27 men after their wooden sailing ship was crushed by ice in the Weddell Sea. Most of the group hunkered under their upturned lifeboat on a forlorn, frozen beach for months, eating raw penguins and seals, amputating each other’s miserably frostbitten toes, while Shackleton and a few men made a legendary open-boat crossing to South Georgia and eventually returned with a rescue ship. It’s a timeless tale of leadership and survival against all odds.

But Antarctica’s age of heroic exploration has passed, and today the only trace of Shackleton’s adventure on Elephant Island is a bronze statue of the Chilean captain who picked up the crew. The island is desolate and seldom visited. On this 29-mile-long outcrop of rock and glacier, surrounded by the brooding Southern Ocean, it’s easy to feel that nothing at all has changed in the past hundred years.

But things are changing down here. According to NASA data, midwinter temperatures around the Antarctic Peninsula have spiked by nearly 5°C in the past five decades, ranking this region among the fastest-warming areas on Earth. The physical effects are about what you’d expect: Ice shelves spectacularly shattered, glaciers retreated, and sea ice dwindled. Shackleton could never have predicted that people following in his footsteps would worry far less about personal safety and far more about Antarctica itself falling apart.