A fifth year of disappointing snow in the Sierra is part of a much larger predicament of record-low snow across the Northern Hemisphere, a setback that scientists identified Wednesday as another reminder of the alarming pace of human-caused global warming.

A panel of climate experts organized by SEARCH, or the Study of Environmental Arctic Change, met in Washington, D.C., to draw attention to the historic melt-off of snow and ice during the first six months of 2016 — and the resulting problems.