The annual peak of global heat-trapping carbon dioxide
in the atmosphere has reached a new perilous level: it is now 50% higher than when the industrial age began.
Scientists reported on Monday that the average rate of increase is faster than ever.
According to NOAA climate scientist Pieter Tans, the average carbon dioxide level for May was 419.13 parts per million, 1.82 parts per million higher than May 2020 and 50% higher than stable pre-industrial levels of 280 parts per million.
Carbon dioxide levels peak every May, just before plant life in the Northern Hemisphere blossoms, sucking some of that carbon out of the atmosphere and into flowers, leaves, seeds, and stems; however, the reprieve is only temporary, because carbon dioxide emissions
from burning coal, oil
, and natural gas
for transportation and electricity far exceed what plants
can take in, pushing greenhouse gas
“Reaching 50% higher carbon dioxide than preindustrial levels is really setting a new benchmark, and not in a good way,” said Natalie Mahowald, a climate scientist at Cornell University who was not involved in the study. “If we want to avoid the worst consequences of climate change
, we need to work
much harder to cut carbon dioxide emissions right away.”
Climate change does more than raise temperatures; it causes extreme weather
— storms, wildfires
, floods, and droughts — to become worse and more frequent, and it causes oceans to rise and become more acidic, according to studies. There are also health
consequences, such as heat deaths and increased pollen.
The one-year increase in carbon dioxide was not a record, owing to a La Nina weather pattern that causes parts of the Pacific to temporarily cool, according to Scripps Institution of Oceanography geochemist Ralph Keeling. Keeling's father began monitoring carbon dioxide on top of the Hawaiian mountain Mauna Loa in 1958, and he has continued the work of charting the now-famous Keeling Curve.
According to Scripps, which calculates the numbers differently based on time and averaging, the peak in May was 418.9.
Earlier studies also found that pandemic
lockdowns slowed transportation, travel, and other activity by about 7%, but this was too small to make a significant difference. Because carbon dioxide can stay in the air for 1,000 years or more, year-to-year changes in emissions don't register much.
The 10-year average rate of increase also reached a new high, reaching 2.4 parts per million per year.
“Carbon dioxide increasing by about 80 parts per million in a few decades is extremely unusual,” Tans said. “For example, when the Earth climbed out of the last ice age, carbon dioxide increased by about 80 parts per million, and it took the Earth system, the natural system, 6,000 years. We have a much larger increase in the last few decades.”
In comparison, from 1979 to 2021, it only took 42 years to increase carbon dioxide by the same amount.
“The world is approaching the point where exceeding the Paris targets and entering a climate danger zone becomes almost inevitable,” said Michael Oppenheimer, a climate scientist at Princeton University who was not involved in the research