Climate change imperils upper Mississippi River backwaters. Now nature needs human help.

ALMA, Wisconsin — It's an overcast day in February, and two Wisconsin Department of Natural Resources staffers trek over the ice covering some backwaters of the Mississippi River in Alma.

Using GPS coordinates, they locate the exact spot they visited a few months earlier. 

Jeremy King, a water quality technician, drills a hole through the ice. Then he and water quality specialist Shawn Giblin start taking measurements.