Keeling Curve

The Keeling Curve is a daily record of global atmospheric carbon dioxide (CO2)concentration maintained by Scripps Institution of Oceanography at UC San Diego.

The concentration of CO2 in the atmosphere increases every year, and the rate of increase is accelerating. Monthly CO2 values at the Mauna Loa observatory first breached the 400 ppm threshold in 2014. Atmospheric carbon dioxide continued to increase with the average for May peaking at 414.8 parts per million (ppm) in 2019.

This is the highest seasonal peak recorded in 61 years of observations on top of Hawaii’s largest volcano, and the seventh consecutive year of steep global increases in concentrations of carbon dioxide, or CO2. The 2019 peak value was 3.5 parts per million higher than the 411.3 ppm peak reached in May 2018 and represents the second-highest annual jump on record. The latest CO2 reading may be viewed here.