Artist Xavier Cortada favors an unusual medium: polar ice.

In 2006, during 2 weeks in Antarctica, he took scientists’ samples from the West Antarctic Ice Sheet, mingled them with paint, and let them melt on paper. “It’s a watercolor if you think about it,” Cortada says, and “a precursor of horrors to come” with global warming.

In a performance piece at the South Pole, Cortada read 24 statements about climate change, collected from people around the world, over 24 shoes aligned with their longitudes. He also planted 51 fl ags 10 meters apart to mark how ice has flowed yearly from the pole since 1956, when humans opened a permanent base there, and buried an ice replica of a mangrove seedling under the pole itself. Cortada called the latter installation “150,000-Year Journey”—the time the ice will take to convey the seedling to the continent’s edge.  “It’s my way of … making us realize how insignificant [human history] was next to geologic time scales,” he says.

Artifacts, photos, and video from Cortada’s projects appear in North Pole/South Pole (90n/90s) Installations, an exhibition that opened 25 June at the Miami Science Museum in Florida.