With December's crucial Copenhagen climate change summit fast approaching, we talk to 350.org founder Bill McKibben about the politics of climate change in the US, the challenges of building a successful mass movement, and how we set about not only restricting the amount of new CO2 we're pumping into the atmosphere, but reducing the levels that are already there.
350 is the number that leading scientists say is the safe upper limit for carbon dioxide in our atmosphere - it's measured in "Parts Per Million". So below 350 ppm is where we need to be to avoid runaway climate change. Currently the figure is around 390 and rising.
350.org will coordinate an international day of action on October 24 at hundreds of iconic places around the world - from the Taj Mahal to the Great Barrier Reef - with the aim of sparking a global movement to unite the public, media, and our political leaders behind the 350 goal.
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