SOURCE: New York Times

DATE: April 17, 2019

SNIP: When it was built in the early 1900s, the road into Mount Rainier National Park from the west passed near the foot of the Nisqually Glacier, one of the mountain’s longest. Visitors could stop for ice cream at a stand built among the glacial boulders and gaze in awe at the ice.

The ice cream stand is long gone. The glacier now ends more than a mile farther up the mountain.

As surely as they are melting elsewhere around the world, glaciers are disappearing in North America, too.

This great melting will affect ecosystems and the creatures within them, like the salmon that spawn in meltwater streams. This is on top of the effects on the water that billions of people drink, the crops they grow and the energy they need.

Glacier-fed ecosystems are delicately balanced, populated by species that have adapted to the unique conditions of the streams. As glaciers shrink and meltwater eventually declines, changes in water temperature, nutrient content and other characteristics will disrupt those natural communities.

“Lots of these ecosystems have evolved with the glaciers for thousands of years or maybe longer,” said Jon Riedel, a geologist with the National Park Service who has established glacier monitoring programs at Rainier and other parks.

Streams that are mostly fed by glacial meltwater often have unique species that have adapted to the cold conditions. Reducing or eventually eliminating the contribution of this meltwater will raise stream temperatures. Even a small temperature increase can have potentially negative effects.

“Certain species like cold water,” said Alexander M. Milner, a professor of river ecosystems at the University of Birmingham, in England, who has studied the changes wrought by shrinking glaciers for years.

“When the glaciers disappear, those species will go extinct,” he said.