There is of course a huge amount of observational data which confirms this, but in addition, you only have to look at the ‘then and now’ photos of the world’s glaciers to see that they are melting.
Glacier mass results from the accumulated balance of new snowfall, minus annual melt. While snowfall is a product of complex localised precipitation patterns, melt is almost entirely influenced by temperature. The hotter it is on average, the more ice will melt. Simple physics !
It’s a fact that the majority of the world’s glaciers are in retreat, and have been for over 150 years.
Apart from being an obvious visual indicator of global warming, this large scale loss of stored frozen fresh water is causing concern due to increasing drinking water shortages, flooding risks, and global sea level rise.
Photo by via Wikicommons