Climate change can be hard to visualize, because it tends to happen at a relatively creeping pace, not in one dramatic surge, as Hollywood often likes to depict.
But new photos from NASA flights provide a fresh look at melting ice. For the past eight years, NASA has been flying Operation IceBridge missions in research planes over the poles, in order to gather more visual data on the impact of warming temperatures.
To help make this work more accessible to the public, in late October, photographer Mario Tama flew on three of NASA's IceBridge flights over Western Antarctica and the surrounding sea ice, leaving out of Punta Arenas, Chile. The trip was timed to coincide with the start of the melt season (spring) in the Southern Hemisphere.
The photos couldn't be more timely, since NASA and University of California, Irvine scientists have recently reported the fastest retreats of Western Antarctica's glaciers yet recorded.
Tune in to National Geographic's special new series on Antarctica, Continent 7, later this month.
A study published on October 25, drawing on IceBridge data, found that warm water is melting the undersides of the ice sheets. This could cause the large buttresses holding up vast amounts of ice to fail, leading to a rapid release of ice into the sea, along the lines of pancake batter flattening out.
If all the ice on the world's land melted it would raise sea level about 216 feet. Scientists have estimated melting all that ice could take 5,000 years, although the precise rate is hotly debated. How much the world is able to hold down carbon emissions will also strongly affect the rate of melting, scientists warn.
Flying in an "old, sturdy, beautifully reliable DC-8," Tama was most struck by the massive scale of the existing ice.
"Occasionally one could spot a seal or a penguin, but they were so tiny amidst the never-ending landscape that they were essentially impossible to photograph," he says.
"At times it really felt like a lunar mission, or a mission to Venus," says Tama. "The scenes, shapes, and sizes of the features in Antarctica were often otherworldly ... and just insanely, unimaginably beautiful."
NASA flight crew members work inside the cockpit of the Operation IceBridge DC-8 research airplane. Photograph by Mario Tama, Getty
Such a sea of ice had once covered North America during the last ice age, a reminder of how variable climate can be over time, and how just a few degrees in average temperature can make a huge difference in the landscape.
Tama says his goal was to "document this slice of the planet that is alien to most of us." He adds, "I hope my photographs will in some small way support the incredibly important work the scientists are doing. These folks are the heroes.