Time Lapse Reveals The Retreating South Cascade Glacier in Washington

Today, Pacific salmon are facing another threat could drive them to the brink of extinction. Salmon need the glacier-fed streams of the Northwest to survive, but since 1920, the average annual temperature in the region has risen by 1.5 degrees Fahrenheit. That slight increase in temperature has caused the glaciers of the South Cascades to shrink to half what they were a century ago, according to the United States Geological Survey.