What former presidential candidate has won a Noble Peace Prize but has never been president of U.S.?

Al Gore is the former presidential candidate who is a recipient of the Nobel Peace Prize (together with the Intergovernmental Panel on Climate Change). He received the award in 2007. Al Gore and the IPCC won the award "for their efforts to build up and disseminate greater knowledge about man made climate change, and to lay the foundations for the measures that are needed to counteract such change". The award received criticism on the grounds of political motivation and because the winners' work was not directly related to ending conflicts in the world.

Specifically, Albert Arnold "Al" Gore Jr. (born March 31, 1948) is an American politician and environmentalist who served as the 45th Vice President of the United States from 1993 to 2001 under President Bill Clinton. After leaving office, Gore has remained prominent as an author and environmental activist.