The World Resources Institute has posted a really well-done interactive visualization on the history and the sources of human-caused CO2 emissions.  Read more at http://grist.org/climate-energy/heres-a-cool-way-to-visualize-carbon-emissions/

One uncomfortable fact that is made very clear by this: the U.S. has been the biggest emitter for a long, long while. China’s recent ascension shouldn’t distract from America’s enormous share of the responsibility for this problem (which, ironically, will probably impact America least, at least at first).