Choose the number 350-as in parts per million CO2. Scientists say that 350 parts per million CO2 in the atmosphere is the safe limit for humanity. 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 victory and where we need to head as a planet.We work hard to organize in a new way--everywhere at once. In October of 2009, 350.org coordinated 5200 simultaneous rallies and demonstrations in 181 countries, what CNN called the 'most widespread day of political action in the planet's history.' In October 2010 they are organizing a 'global work party' all over the world. People will put up solar panels, dig community gardens--and send a strong message to our leaders: 'If we can get to work on solutions to the climate crisis, so can you.'The theory of change is simple: if an international grassroots movement holds our leaders accountable to the latest climate science, we can start the global transformation we so desperately need. Less