Atmospheric Carbon Dioxide Levels Reach New High

Peak monthly average of 421 parts per million is 50 percent greater than pre-industrial levels. Carbon dioxide measured at NOAA's Mauna Loa Atmospheric Baseline Observatory peaked in May 2022 at an average of more than 420 parts per million, pushing the atmosphere further into territory not seen for millions of years, scientists from NOAA and Scripps Institution of Oceanography at the University of California San Diego announced today. In May, Scripps Oceanography's measurements of carbon dioxide, or CO₂, at the mountaintop observatory on Hawaii's Big Island averaged 420.78 parts per million (ppm). Scientists at NOAA calculated a monthly average of 420.99 ppm based on independent measurements at the same location. "It's depressing that we've lacked the collective willpower to slow the relentless rise in CO₂," said Scripps geochemist Ralph Keeling, who manages the iconic record of CO₂ concentrations in the atmosphere named the Keeling Curve for his father, Charles David Keeling. "Fossil-fuel use may no longer be accelerating, but we are still racing at top speed towards a global catastrophe." "The science is irrefutable: humans are altering our climate in ways that our economy and our infrastructure must adapt to," said NOAA Administrator Rick Spinrad. "We can see the impacts of climate change around us every day.