New record! The average carbon dioxide levels in the atmosphere has been measured at over 420 ppm since the Mauna Loa Observatory in Hawaii began measuring the average carbon dioxide levels in 1958. This is an increase from 419.13 during the same period last year and an increase from 375.93 if you compare how the level was 20 years ago. We must stop this now! Source: https://gml.noaa.gov/ccgg/trends/