Carbon dioxide peaks near 420 parts per million at Mauna Loa observatory

Atmospheric carbon dioxide measured at NOAA’s Mauna Loa Atmospheric Baseline Observatory peaked for 2021 in May at a monthly average of 419 parts per million (ppm), the highest level since accurate measurements began 63 years ago, scientists from NOAA and Scripps Institution of Oceanography at the University of California San Diego announced today. Scripps’ scientist Charles David Keeling initiated […]