Oct. 24, 2009: Demonstrators spell out "350" on the steps of the Sydney Opera House as part of the International Day of Climate Action. Organized by 350.org, the event had people around the world assembling to support global action to reduce carbon emissions.
Maracaibo, Venezuela. Demonstrators formed the number 350 because scientists have identified 350 parts per million as the safest maximum level of carbon dioxide in the atmosphere.
350.org/Courtesy of Alonso JosÃ© Lizaraz SÃ¡nchez
A week before the demonstrations, 350.org helps organize the first-ever underwater cabinet meeting in Maldives. Here, a minister signs a declaration calling for coordinated global action on climate change.
Students in Punjab, India. The events were organized ahead of an international climate change summit in Copenhagen this December.
Demonstrators gather on Parliament Hill in Ottawa,
Angkor Wat, Cambodia.
Demonstrators form a sun in Ciudad de Mexico.
350.org/Sara Ravelo/ Spectral Q
Students gather in Addis Ababa, Ethiopia.
The Green Long March movement, China's largest youth conservation movement, partners with 350.org for the event.
Demonstrators in Alymay, Kazakhstan climb the Kok-Tobe Mountain.
Times Square in New York City.
350.org/Shadia Fayne Wood
Galatasaray Square in Istanbul, Turkey.
350.org/Sena Ozfiliz (Sightliner Photography)
Kayakers use their boats to spell out "350" in Portland, Oregon.
A meadow 40 kilometers north of Copenhagen.
Outside Cairo, Egypt.
Activists walk down the Royal Mile toward Parliament in Edinburgh, Scotland.
350.org/Peter J Clarke