In order to reduce the urban heat island effect and save air-conditioning energy, the Seoul metropolitan city government will commence on a campaign to paint the rooftop in white color. To this end, the city government on August 28 appointed “Rooftop Moonlight,” a female duet, as honorary ambassadors for the cause. Painting the rooftop in white can substantially reduce energy requirements for the building by taking advantage of the heat reflection effect. The U.S. federal government is also actively encouraging this as a way to conserve energy. American President Barack Obama once remarked, “Cool roofs are one of the best greenhouse gas reduction strategies.” Some U.S. local governments such as the state of California and the city of Dallas have introduced bills to mandate cool roofs for newly built or renovated buildings. The New York City government also made it obligatory to install cool roofs in more than 75 percent of newly built buildings in terms of rooftop area. Cool roof initiatives have gained so much momentum in the United States that 13 states have offered financing programs for building owners while 14 states provide subsidies to owners who implement cool roof projects. Cool roof is applicable to all kinds of roofs while tree planting on the roof is only possible when the roof is built with concrete. In Korea, the Changwon city government (South Gyeongsang Province) has implemented an experimental program in its roofs.