Areas across the globe have seen spring snowpack shrink over the last 40 years, and a new study says for many of them climate change is clearly to blame. Wednesday's study in the journal Nature finds a key threshold for the future of snowpacks in the Northern Hemisphere: 17.6 degrees. In places where the winter averages colder than that, often the snowpack survives because it’s cold enough. But areas warmer than 17.6 degrees for a winter average, like the Upper Colorado River basin, tend to see their winter wonderland dreams melt. And it's bad news for water supply.
