Life Expectancy vs Carbon Dioxide Emissions
Each circle represents a country. Slide the "Life Expectancy" bar to see at which age countries disappear, then click the "Carbon Emissions" button to overlay each country's carbon emissions. Slide the "Life Expectancy" bar again to see the relationship between each country's life expectancy and carbon emissions.
See video of how it works here: http://vimeo.com/33578233