Many glaciers letting rivers run low, others are falling apart
The melting of glaciers around the world is one of the hardest to ignore impacts of climate change (unless you don’t believe your eyes). While worries about rising sea levels are focused on the massive ice sheets of Greenland and Antarctica, the loss of small mountain glaciers comes with its own consequences. A pair of studies published this week highlight two such impacts—one extremely common, one extremely unusual.
The first study, by Matthias Huss and Regine Hock, looks at the effect shrinking glaciers have on local water supplies. Glaciers help sustain rivers downslope through the drier months by providing a constant stream of meltwater, like a frozen water tower that collects in the winter and rations it out over the summer.
For a while, a shrinking glacier will contribute even more meltwater runoff to the river, but there comes a point when a smaller glacier can't keep up. Once it produces less meltwater, it’s downhill to “peak runoff” from there. This process has already been observed at a number of glaciers, but a global picture had not yet been painted.