text:  Over the last 30 years, concentrations of toxic metals like iron, zinc, and copper have doubled in some of Colorado's high mountain streams. As member station KUNC's Ray Solomon reports, researchers say it's all due to a warming climate. With rising temperatures, some streams and rivers in the high Rocky Mountains are growing more acidic and polluted with higher concentrations of heavy metals. That hurts ecosystems, killing plants and aquatic wildlife, and it could become a problem for drinking water.