As a philanthropist, he is known for his $1 billion gift to support the United Nations, which created the United Nations Foundation, a public charity to broaden U.S. support for the UN. Turner serves as Chairman of the United Nations Foundation board of directors. Additionally, in 2001, Turner co-founded the Nuclear Threat Initiative with US Senator Sam Nunn (D-GA). NTI is a non-partisan organization dedicated to reducing global reliance on, and preventing the proliferation of nuclear, chemical, and biological weapons. He currently serves as Co-Chairman of the Board of Directors.