Nature World: Soot, also known as black carbon, could have been the reason behind the abrupt retreat of the mountain glaciers in the Alps starting in the 1860s, according to a new study published in the journal Proceedings of the National Academy of Sciences.
If correct, the theory could solve a longstanding scientific debate as to why the glaciers began melting even decades before global temperatures started rising.
Records dating back to the 1500s show that large valley glaciers in the Alps suddenly melted...