The UN Secretary-General who signed John McConnell’s Earth Day Proclamation was U Thant.
U Thant, a diplomat from Burma, served as the United Nations’ third secretary-general from 1961 to 1971. He was known for supporting international cooperation and humanitarian causes, making his association with an Earth-centered peace initiative historically fitting.
McConnell prepared a worldwide Earth Day Proclamation in 1970 to express principles and responsibilities for caring for the planet. It was signed by 36 world leaders and prominent figures, including U Thant, anthropologist Margaret Mead, and public servant John Gardner.
This episode belongs to one of Earth Day’s parallel origin traditions. McConnell emphasized a global, peace-oriented observance around the March equinox, while the Nelson-Hayes campaign established the mass American environmental teach-in on April 22. The two traditions later became closely linked under the Earth Day name.