The Keeling Curve represents carbon dioxide concentration measurements taken on Mauna Loa, Hawaii from the late 50's to the present day (more on this below).
"Losing Earth: The Decade We Almost Stopped Climate Change" is an excellent story in the NY Times chronicling a period between 1979 and 1989 when the US and the rest of the world tried and failed to take action that would have seriously addressed climate change (global warming) ...