"In October 1969, at the National UNESCO Conference in San Francisco, John McConnell proposed a global holiday to celebrate Earth's life and beauty and to advance peace. Along with the celebration of life on Earth, he intended Earth Day to alert earthlings about the need for preserving and renewing the threatened ecological balances upon which all life on Earth depends. The proposal won strong support and was followed by an Earth Day Proclamation by the City of San Francisco, and the very first celebration of Earth Day on March 21, 1970. In June 1970, McConnell created the Earth Day Proclamation for worldwide use and awareness. The Earth Day Proclamation declared the principles and responsibilities the signers undertook to care for the Earth. It was signed by 36 world leaders, including UN Secretary General U Thant, Margaret Mead, John Gardner and others. The last signature by Mikhail Gorbachev was added in 2000"
Source:
Wikipedia