Scientists are beginning to understand the sudden loss of sea ice in Antarctica – and there is growing evidence that it represents a permanent shift with potentially catastrophic consequences.

New research shows the Sierra Nevada’s glaciers, which have endured since the last Ice Age, are shrinking rapidly and could disappear within decades. Scientists warn their loss will mark the first time in human history that Yosemite’s granite peaks stand without ice.

High in Colorado’s San Juan Mountains, scientists and conservationists are working to restore rare peat-forming wetlands that store carbon, regulate water flow, and support unique ecosystems — but take centuries to rebuild once damaged.