Afghan Youth Support International Day of Climate Action.

A total of 5,200 actions were held around the world to urge action on climate change, according to who sponsered an International Day of Climate Action this past Saturday. The number, 350, refers to the goal of three hundred fifty parts per million of carbon dioxide emissions in the atmosphere, which is claimed by scientists to be the safe upper limit.

The current level is about 387 parts per million CO2 in the atmosphere. A recent report in the Journal of Science shows that the last time levels were this high was fifteen million years ago.

“The last time carbon dioxide levels were apparently as high as they are today — and were sustained at those levels — global temperatures were 5 to 10 degrees Fahrenheit higher than they are today, the sea level was approximately 75 to 120 feet higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland,” Wrote Aradhna Tripati, a UCLA assistant professor in the department of Earth and space sciences and the department of atmospheric and oceanic sciences.

Events for the International Day of Climate Action were held in 181 countries, on all continents, from pole to pole. The New York Times reported that climbers revealed a banner on a mountain peak in Antarctica, and artists formed the numbers 350 in ice in the Greenland Arctic. Separate groups formed the numbers 350 around the Dead Sea, in Jordan, Israel and Palestinian territory.

Much of the events’ focus was on the anticipated conference in Copenhagen, scheduled for December of this year, which is expected to reach a new treaty on climate change to replace the 1997 Kyoto Protocol. Many negotiations and international meetings have been held in the past few months in anticipation of the Copenhagen conference.

View photos from around the world of the “350” events