350.org – International Campaign for Climate Justice


The 350 campaign launched in the spring of 2008 is dedicated to building an international movement around the number 350 to unite the world around solutions to the climate crisis. The focus on the number 350 stems from the parts per million of CO2 in our atmosphere that scientists have identified as the safe upper limit to maintain human life and civilization on Earth as we know it.

Origin of 350 PPM Atmospheric C02 Target Level

NASA scientist Dr. James Hansen announced his belief in 350 ppm atmospheric carbon dioxide as the safe level for humanity after authoring Target atmospheric CO2: Where should humanity aim?  350  was then taken up by author and activist Bill McKibben  a symbol of where the people of earth need to head  together.

350 Campaign Mission

Our mission is to inspire the world to rise to the challenge of the climate crisis–to create a new sense of urgency and of possibility for our planet.

April 10, 2008

Letter From Bill McKibben

Dear friends,

350 is the red line for human beings, the most important number on the planet. The most recent science tells us that unless we can reduce the amount of carbon dioxide in the atmosphere to 350 parts per million, we will cause huge and irreversible damage to the earth.

We’re planning an international campaign to unite the world around the number 350, and we need your help. We need to make sure that the solutions the world proposes to climate change are to scale with the level of crisis that this number represents. Everyone on earth, from the smallest village to the cushiest corner office, needs to know what 350 means. The movement to spread that number needs to be beautiful, creative, and unstoppable.

What we need most right now are your ideas for how to take the number 350 and drive it home: in art, in music, in political demonstrations, in any other way you can imagine. We will connect actions all around the world and make them add up to more than the sum of their parts–but we don’t have all the ideas and all the inspiration. We need yours.

We could also use your help spreading 350. Can you contact anyone you think might be interested and willing to help–in every country on earth–and send them our way?

Many thanks,

Bill McKibben and the 350.org crew.

P.S.—We’ve raised some money to get this campaign up and running, but to execute a successful international campaign will require more than we’ve got. If you’re in a position to help, please support Project 350 by making a tax-deductible donation to our 501c3 fiscal sponsor, the Sustainable Markets Foundation, by clicking here.


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