Correlation between global temperature and atmospheric CO2 concentration from 1880 to 2012. The thick black line gives the yearly CO2 concentration in parts per million (volumes of CO2 present in 1 million volumes of air) with values along the right vertical axis. The ends of the blue and red lines show the temperature with values along the left vertical axis. The horizontal line shows the average temperature across this time span. The ends of the blue lines show the temperature values for years in which the temperature was below the average, and the ends of the red lines show the temperature values for years in which the temperature was above the average.
© 2014 Henry Auer