 Manning, who works for the U.S. Geological Survey, is here to keep tabs on those unusually high metals and acidity, a phenomenon known as acid rock drainage. His research points to sharp increases. We look specifically at zinc and copper. It amounts to about a doubling of concentrations over the past three decades, and that's substantial. Manning says it's all happening because of changes in the climate. Ground that is normally frozen year-round is now thawing, and the water table dropping.