The LA Times reports:
Black soot from 19th century homes and factories in Europe hastened the end of the Little Ice Age and caused glaciers in the Alps to retreat decades sooner than they would have otherwise, according to a new study.
The black carbon particles caused the snow to absorb more heat, speeding up the melting process. As a result, the glaciers beneath the snowpack were exposed earlier in the year, giving them more time to melt. And glacial ice melts faster than snow, because it is darker.
This story line explains why Alpine glaciers began to retreat around the year 1865, even though temperatures were cooler than they had been over the previous century and there was just as much rain and snow as before. An international team of scientists connected the dots in a study published Monday by Proceedings of the National Academy of Sciences.