What is 350?

350 means safety from the climate crisis.

You might have noticed the number 350 in a lot of photos on the Moving Planet homepage, and you might be wondering what it's all about.

Here's the deal: scientists have determined that to preserve our planet, we must reduce the amount of carbon dioxide (CO2) in the atmosphere from its current level of 392 parts per million ("ppm")to below 350 ppm. You can think of 350 as the "safe upper limit" for carbon dioxide in our atmosphere. But 350 is more than a number—it's a symbol of where we need to head as a planet.

Three years ago, after leading climatologists observed rapid ice melt in the Arctic and other frightening signs of climate change, they issued a series of studies showing that the planet faced both human and natural disaster if atmospheric concentrations of CO2 remained above 350 parts per million.Everyone from Al Gore to the U.N.’s top climate scientist has now embraced this goal as necessary for stabilizing the planet and preventing complete disaster.

350.org is an organization that is dedicated to building a global grassroots movement to solve the climate crisis -- and push for policies that will put the world on track to get to 350 ppm.

350.org helped coordinate Moving Planet day of action but we couldn't have done it without our amazing partners.