The United States Secretary of Energy is the head of the United States Department of Energy, a member of the President's Cabinet, and fifteenth in the Presidential line of succession. The post was created with the formation of the Department of Energy on October 1, 1977 by President Jimmy Carter's signing of the Department of Energy Organization Act. The position was originally developed to focus on energy production and regulation. During the 1980s, the emphasis shifted to development of technology for better, more efficient energy sources as well as education regarding energy. As the Cold War ended, the department's efforts were more often devoted to nuclear waste disposal and maintenance of environmental quality.