Can hiking help science? Every fall, volunteer hikers help study Iceland’s glaciers. The volunteers are members of the Iceland Glaciological Society. There are hikers of all ages—from adults to kids!

Each volunteer tracks a different glacier. During their hike, the volunteers walk until they reach the edge of their glacier. Then they record how far they hiked and compare it to the year before. This information tells them if the glacier has grown or shrunk.

Many of the glaciers have been monitored since 1950. The data shows that over time, most of the glaciers have been shrinking. It’s a sign that our climate is changing, says Bergur Einarsson. He’s a scientist who works with the volunteers.