<Table> <Tr> <Td> </Td> <Td> This biography of a living person needs additional citations for verification . Please help by adding reliable sources . Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful . (May 2014) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This biography of a living person needs additional citations for verification . Please help by adding reliable sources . Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful . (May 2014) (Learn how and when to remove this template message) </Td> </Tr> <P> John Francis (born 1946) is an American environmentalist nicknamed the planetwalker . Born in Philadelphia, the son of a West Indian immigrant, he moved to Marin County, California as a young man . After witnessing the devastation caused by the 1971 San Francisco Bay oil spill, he stopped riding in motorized vehicles, a vow which lasted 22 years from 1972 until 1994 . From 1973 until 1990, he also spent 17 years voluntarily silent . During this time he earned a Ph. D. in land management and traveled extensively, walking across the entire width of the lower 48 states of the USA as well as walking to South America . </P> <P> On January 17, 1971, two oil tankers owned by Standard Oil Company, the Arizona Standard and Oregon Standard, collided in San Francisco Bay, creating an enormous oil spill 840,000 gallons . After seeing the damage caused, John Francis joked with a friend about never riding in a car again . The following year, a neighbor of Francis' died suddenly . Faced with a new sense of the uncertainty of life, Francis decided to act immediately and for the next 22 years refused to ride in motorized vehicles . Francis describes himself as having had an over-inflated sense of self - importance at this time, and says that he initially expected other people to follow his example and also forgo automobiles and other powered vehicles . </P>

Walk the earth my 17 year vow of silence