The National Oceanic and Atmospheric Administration (NOAA) and the Scripps Institution of Oceanography (Scripps) has found that the levels of carbon pollution in Earth’s atmosphere reached another record high last month, as it continues “a steady climb further into territory not seen for millions of years,” according to NOAA. Carbon dioxide levels measured 424 parts per million in May in Hawaii, 3 parts per million more than the average found in May 2022.

It’s the fourth-largest annual increase since recordkeeping began 65 years ago, and 2022 was the at least the sixth-warmest year on record as countries around the world set new national record-high annual averages. “Whatever we’re seeing weather-wise now is just the beginnings of much bigger changes,” Ralph Keeling, a geochemist at Scripps, told the Washington Post.

“We are absolutely at levels unseen in human civilization,” University of Oklahoma meteorology professor Jason Furtado told the AP. “Humans are running a massive experiment on the Earth climate system via burning carbon, and the results are turning out not great for a lot of people on this planet.”  (AP, USA Today, Washington Post $, LA Times $)