350.org is an international campaign that’s building a movement to unite the world around solutions to the climate crisis—the solutions that science and justice demand. The mission surrounds the number 350—as in parts per million CO2. If we can’t get below that, scientists say, the damage we’re already seeing from global warming will continue and accelerate. But 350 is more than a number—it’s a symbol of where we need to head as a planet. to rise to the challenge of the climate crisis—to create a sense of urgency and of possibility for our planet.