A group of environmental activists gathered in San Francisco today in one of thousands of events around the world that are part of a global day of action to urge leaders to address climate change and reduce carbon emissions.

The event in San Francisco was one of more than 5,200 events in more than 180 countries organized by www.350.org, a group of organizations dedicated to climate action.

People laid down near Justin Herman Plaza to create a large ‘350’ with their bodies to symbolize a figure important to climate scientists.

Scientists have insisted in recent years that 350 parts per million of carbon dioxide is the most we can safely have in the atmosphere, according to event organizers. The current concentration is 390 parts per million.

During the event in San Francisco, activists called on President Obama and other world leaders to agree on a deal in Copenhagen in December at the U.N. Climate Change Conference.

“It’s time for President Obama to lead,” Lauren Thorpe, an organizer for Greenpeace, said in a statement. “Global warming is our generation’s greatest challenge, and we’re not going to let our future be decided by the same old politics.”

Other Bay Area events organized by www.350.org today included a sunrise hike up Mt. Diablo and a parade of 350 flag-adorned bicyclists who rode along what is estimated to be San Francisco’s shoreline after it is affected by climate change.

For more information, visit www.350.org.

Please make sure your comment adheres to our comment policy. If it doesn't, it may be deleted. Repeat violations may cause us to revoke your commenting privileges. No one wants that!