(Portland, OR)  --  A new forecast by the Northwest Power and Conservation Council predicts the closures of three coal-fired power plants would considerably shrink the Northwest's carbon footprint over the next 20 years.  The report says closing those plants in Boardman, Oregon; Centralia, Washington; and Valmy, Nevada, would reduce the region's carbon footprint from about 55-million metric tons annually to 34-million metric tons by 2035.  The "Spokesman Review" reports the forecast, which is part of the draft Northwest Power Plan, also assumes that the region will continue pursuing aggressive energy-efficiency to decrease new demand.