Keeling Curve

(graphic above embedded from only as an example of the charting tech.)

Today's Reading:  396.4

One of the first and most-recognized indicators of society's impact on climate is the "Keeling Curve," a measurement of CO2 concentrations in the atmosphere began by Charles David Keeling, a geochemist at Scripps Institution of Oceanography, UC San Diego. Keeling set up ultraprecise measurement devices atop Hawaii's Mauna Loa and in March 1958 made a reading of 311 parts of carbon dioxide per million of air. That was already elevated from an average concentration of 280 ppm before the onset of the Industrial Revolution. Now, as the concentration approaches 400 ppm, Scripps Institution of Oceanography at UC San Diego, offers a daily update of this bellwether measure and an explanation of what makes it fluctuate and rise. 

Climate scientists have identified a return to 350 ppm as a target for avoiding negative climate change consequences. They have also identified 450 ppm as a threshold beyond which society can expect to experience dangerous climate change consequences.