Can anyone explain how to read the CO2 vs GDP graph near the bottom of the article?  Is there a name for this type of graph?<p><a href="http:&#x2F;&#x2F;breakthrough.turing.com&#x2F;images&#x2F;elements&#x2F;Figure_13.png" rel="nofollow">http:&#x2F;&#x2F;breakthrough.turing.com&#x2F;images&#x2F;elements&#x2F;Figure_13.png</a>