A crown-shaped iceberg drifts under the soft glow of an Antarctic sunset. During the Southern Hemisphere’s winter, the ice continent is plunged into darkness where the sea ice creates a vast shelf of snowy ridges and platforms. As the summer returns, bringing the pale light off the midnight sun, the ice breaks apart, and intricate ice sculptures like this one slip into the sea. To most of us, Antarctica can feel like this distant, wild realm far beyond our reach. In truth, every one of us depends on the healthy cycles of sea ice to fuel our ocean’s currents and stabilize our global climate.