Carbon dioxide levels have risen by 50% from pre-industrial times
Published : 08 Jun 2021, 18:01
The annual peak of heat-trapping carbon dioxide in the atmosphere has surpassed yet another alarming milestone: it is now 50% higher than it was when the industrial age began.
Scientists stated Monday that the average rate of rise is faster than it has ever been.
The National Oceanic and Atmospheric Administration said the average carbon dioxide level for May was 419.13 parts per million. That’s 1.82 parts per million higher than May 2020 and 50% higher than the stable pre-industrial levels of 280 parts per million, said NOAA climate scientist Pieter Tans.
Carbon dioxide levels in the atmosphere reach their highest point in May, just as plant life in the Northern Hemisphere blooms, pulling some of the carbon out of the sky and into flowers, leaves, seeds, and stems. However, the relief is only short because carbon dioxide emissions from the burning of coal, oil, and natural gas for transportation and electricity greatly exceed what plants can absorb, causing greenhouse gas levels to rise to new highs every year.
“Reaching 50% higher carbon dioxide than preindustrial is really setting a new benchmark and not in a good way,” said Cornell University climate scientist Natalie Mahowald, who wasn’t part of the research. “If we want to avoid the worst consequences of climate change, we need to work much harder to cut carbon dioxide emissions and right away.”
Climate change has an impact on more than just the temperature. Storms, wildfires, floods, and droughts become worse and more frequent, and oceans rise and become more acidic, according to studies. There are also health consequences, such as increased pollen and heat fatalities. Countries signed the Paris Agreement in 2015 to try to keep climate change to a minimum level.
The one-year jump in carbon dioxide was not a record, mainly because of a La Nina weather pattern, when parts of the Pacific temporarily cool, said Scripps Institution of Oceanography geochemist Ralph Keeling. Keeling’s father started the monitoring of 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.
Scripps, which calculates the numbers slightly differently based on time and averaging, said the peak in May was 418.9.
Also, pandemic lockdowns slowed transportation, travel and other activity by about 7%, earlier studies show. But that was too small to make a significant difference. Carbon dioxide can stay in the air for 1,000 years or more, so year-to-year changes in emissions don’t register much.
The 10-year average rate of increase also set a record, now up to 2.4 parts per million per year.
“Carbon dioxide going up in a few decades like that 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.”
By comparison, it has taken only 42 years, from 1979 to 2021, to increase carbon dioxide by that same amount.
“The world is approaching the point where exceeding the Paris targets and entering a climate danger zone becomes almost inevitable,” said Princeton University climate scientist Michael Oppenheimer, who wasn’t part of the research.
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