It is one of the largest annual May-to-May increases in carbon dioxide levels on record, behind only 2016 and 2019, which had jumps of 3.7 and 3.4 parts per million.
“The relentless rise in atmospheric CO2 is incredibly worrying if not wholly predictable,” said Brown University climate scientist Kim Cobb, who was not part of the research. There are two main ways of tracking greenhouse gases. One is to monitor what’s coming out of smokestacks and exhaust pipes, but about half of that is absorbed by the oceans and lands, Andrews said.
Because of that “we are still dealing with CO2 in the atmosphere that was emitted in the early-to-mid 20th century,” University of Oklahoma meteorology professor Jason Furtado, who wasn't part of the monitoring teams, said in an email. “This is why we have to see emissions DROP in order to have a chance to reverse climate change. And even if/when we reverse the CO2 emissions rate, it will take some time before the climate system responds.