Taking Inventory of Two Hundred Thousand Melting Glaciers

There are 200,000 glaciers in the world. Combined, they would cover an area about the size of Texas, and they contain enough water to raise the sea level well over a foot. That's important, because many of these glaciers are melting, and some of them are melting very quickly.

As soon as it became apparent that was the case, glaciologists set out to take inventory of the world's monolithic ice stock. They have now completed the most comprehensive satellite mapping of the planet's glaciers, and published the findings in the Journal of Glaciology. Scientists will now use the detailed maps of hundreds of thousands of glaciers to determine what will happen as they fade.

"In addition to impacting global sea rise, the melting of the world’s glaciers over the next 100 years will severely affect regional water resources for uses like irrigation and hydropower," University of Colorado glaciologist Tad Pfeffer said, in a statement. He also said that the melting is likely due to “glacier outburst” floods as the ice mass warms and shrinks.

The 14-18 inches of sea level rise that the world's glaciers stand to unleash may seem paltry compared to the 200 feet's worth locked away in Greenland and Antarctic ice sheets.

“But in the first several decades of the present century it is going to be this glacier reservoir that will be the primary contributor to sea rise," Pfeffer said. "The real concern for city planners and coastal engineers will be in the coming decades, because 2100 is pretty far off to have to make meaningful decisions.”

Meanwhile, many communities depend on glacial runoff for agriculture and drinking water. As glaciers melt away, so does a crucial resource that civilizations have depended on for hundreds of years. Some of them will be gone in decades.

A few years ago, I took a two-day hike in the Kashmiri Himalayas, a place where glacier melt is of particularly great concern. At the highest point of our climb, we came upon a glacier, its teardrop waterfall feeding into an alpine lake. You could infer from the coloration of the rocks below it how much it had receded; in a place full of mighty, craggy things, it looked small and pathetic. It didn't look long for the world.

The glacier, this thing that is supposed to epitomize slow-movingness and frozen permanence, is in the process of having its definition scrambled entirely. Future generations will no doubt know glaciers not as something that is sluggish, but as something that is melting, inexorably. At least science can help us plan for the slush.