Author Bill McKibben never saw this coming.
Founder of 350.org, an environmental campaign aimed at holding atmospheric carbon dioxide concentrations below 350 parts-per-million, McKibben sent word that this Saturday would be the day to take to the streets.
The call went viral in ways far beyond anything McKibben and fellow organizers imagined: As of Thursday morning some 4,317 actions and rallies are planned in 171 countries, with 300 events in China, 1,500 across the United States, 500-plus in Central and South America.
Organizers credit the increasing inter-connectedness of Web, cellular and social networks for the spread, saying such random and organic growth would have been impossible even two years ago.
