Carbon dioxide levels measured at NOAA’s Mauna Loa Baseline Atmospheric Observatory rose by 3 parts per million to 405.1 parts per million (ppm) in 2016, an increase that matched the record jump observed in 2015.
The two-year, 6-ppm surge in the greenhouse gas between 2015 and 2017 is unprecedented in the observatory’s 59-year record. And, it was a record fifth consecutive year that carbon dioxide (CO2) rose by 2 ppm or greater, said Pieter Tans, lead scientist of NOAA's Global Greenhouse Gas Reference Network.
