Global warming could spell big trouble for Canada’s freshwater supply, according to a report from the government agency Natural Resources Canada. The predicted global surface-air temperature increase of between 2.5 and 10.4 degrees Fahrenheit over the next century would sap some of the country’s hydroelectric power potential, lower lake levels, and pave the way for severe drought on the Canadian prairies, the report warns. Parts of the prairies are already suffering their second and third consecutive summer droughts. Other problems could include stranded docks and harbors as water levels drop; decreased potable water supplies; reduced fish habitat and possible species loss; financial troubles for agriculture; and the complete disappearance of some Arctic and sub-Arctic lakes. The report comes out as the Canadian government continues to waver on whether to ratify the Kyoto Protocol on climate change.