The last rays of sun filter through the snow-covered spruces along the shore of Goldstream Lake, just outside Fairbanks, Alaska. Out on the lake Katey Walter Anthony stares at the black ice beneath her feet and at the white bubbles trapped inside it. Large and small, in layer upon layer, they spread out in every direction, like stars in the night sky. Walter Anthony, an ecologist at the University of Alaska Fairbanks, grabs a heavy ice pick and wraps the rope handle around her wrist. A graduate student holds a lighted match above a large bubble; Walter Anthony plunges the pick into it.
Gas rushing from the hole ignites with a whoomp that staggers her. “My job’s the worst, because usually you catch on fire,” she says, smiling. In the gathering twilight she and her team ignite one bubble after another.
The flames confirm that the bubbles are methane, the main component of natural gas. By counting and measuring them, Walter Anthony is trying to gauge how much methane is rising from Goldstream Lake—and from the millions of similar lakes that now occupy nearly a third of the Arctic region. The Arctic has warmed much faster than the rest of the planet in recent decades, and as the permafrost has melted, old lakes have grown and new ones have formed. Methane bubbles from their muddy depths in a way that is hard to quantify—until the first clear ice of fall captures a snapshot of the emissions from an entire lake.