According to Flags of the World, the Ecology Flag was created by cartoonist
Ron Cobb, and was published on November 7th, 1969, in the Los Angeles Free Press
and then placed it in the public domain.
The symbol was a combination of the letters "E" and "O"
taken from the words "Environment" and "Organism", respectively.
The flag was patterned after the flag of the United States, and had thirteen
stripes alternating green and white. Its canton was green with a yellow theta.
Later flags used either a theta because of its historic use as a warning symbol,
or the peace symbol. Theta would later become associated with Earth Day.
As a 16-year-old high school student, Betsy Vogel, an environmental advocate
and social activist that enjoyed sewing costumes and unique gifts, made a 4
x 6-foot (1.8 m) green and white "theta" ecology flag to commemorate
the first Earth Day.
Initially denied permission to fly the flag at C. E. Byrd High School in Shreveport,
Louisiana, Vogel sought and received authorization from the Louisiana State
Legislature and Louisiana Governor John McKeithen in time to display the flag
for Earth Day.