"Glaciers in the Alps of Europe pose a scientific mystery. They started melting rapidly back in the 1860s. In a span of about 50 years, some of the biggest glaciers had retreated more than half a mile."
"But nobody could explain the glacier's rapid decline. Now, a new from NASA's Jet Propulsion Laboratory uncovers a possible clue to why the glaciers melted before temperatures started rising: Soot from the Industrial Revolution could have heated up the ice.
Scientists trying to understand Europe's climate for the past several hundred years have turned to the glaciers in the Alps because they preserve some of the temperature and precipitation history during that time."