Starting with Los Alamos, repeated atomic explosions altered the isotopic composition of the Earth's atmosphere in a way that is easily seen in historic proxyindicator records such as ice cores, lake cores, tree rings, and so on.
Recently raised cores from the Himalayan ice fields, when analyzed, failed to show this global signal. This strongly suggests that these ice fields have not grown during the last fifty years, or more.
The ice fields provide an important buffer in the headwaters of major rivers relied on today for agriculture and other uses by a very large number of people.
Similar findings have occurred elsewhere. For instance, it is predicted that the glaciers on Kilimanjaro, in Tanzania, will be gone in about 7 to 10 years from now. Eighty percent of the 15,000 or so mountain glaciers in the Himalayas are expected to be melted away in about twenty to twenty five years from now.
Details here.
Whilst, ironically, the pace at which we're trying to combat global warming is...glacial!