One of the most amazing settings in the National Park System are glacial landscapes. From Glacier National Park in Montana and Mount Rainier National Park in Washington state to Alaska, these rivers of ice are captivating to see and, if you're lucky enough, to walk upon or watch as they calve blocks of ice into Pacific waters.

But as amazing as these rivers of ice are, they are vanishing under the warmth of climate change. Glacier National Park's glaciers could be gone by mid-century. Many of those in Alaska are almost visibly in retreat.

But how serious is the problem, what is the overall state of glacial ice in the Park System? Two researchers, Deborah Kurtz from the National Park Service and Taryn Black, a doctoral student in Earth and Space Sciences at the University of Washington, have tried to answer that question as it applies to Kenai Fjords National Park two hours south of Anchorage, Alaska. We're joined today by Taryn Black.