An article in the New York Times (Sept 16, 2011) describes continued resistance by consumers to doing their laundry in cold water – just 7 % of US white laundry loads.  About 75 % of the energy used,and greenhouse gases impact, of laundry comes from the hot water use during laundry. New detergents have been formulated to enable cold water laundry to achieve the same results as hot water, but sales of such detergents declined 16 % for Henkel and 5 % for P&G in recent years. Should consumers be penalized for use of hot water beyond their energy bills ? Should coldwater detergents be subsidized by governments because of the externality benefits they create through greenhouse gas reduction ?  Should laundry machine designs encourage consumers to shift their preferences ? How should the detergent supply chain be managed to improve its environmental footprint ?