A FORA.tv interview with author, educator and environmentalist Bill McKibben @ COP15 lead me to to Mission 350 + their animation about the amount of CO2 in our atmosphere.
In the FORA.tv interview, Mickibben pairs some concrete numbers with the intense sense of urgency that most of the speakers (who are truly seeking a solution) at COP15 are emphasizing.
Check out the interview http://tinyurl.com/y8ldopm