Levels of carbon dioxide and methane in the atmosphere reached historic highs last year and are increasing at a near-record pace, according to the latest data from the National Oceanic and Atmospheric Administration. The Associated Press reports: Carbon dioxide, the most important and abundant human-caused greenhouse gas, increased in 2023 by the third largest increase in 65 years of record, NOAA announced Friday. Scientists are also concerned about rapidly rising atmospheric levels of methane, a short-lived but more powerful heat-trapping gas. Both have risen 5.5% over the past 10 years. The 2.8 parts per million increase in atmospheric carbon dioxide concentrations from January to December 2023 was smaller than the increases in 2014 and 2015, but larger than every other year since accurate records began in 1959. The average level of carbon dioxide in 2023 was 419.3 ppm, an increase of 50% since pre-industrial times.
Last year's 11.1 ppb increase in methane was lower than the record annual increase from 2020 to 2022. Last year's average was 1922.6 ppb. According to Xin “Lindsay” Lan, an atmospheric scientist at the University of Colorado and the National Oceanic and Atmospheric Administration who conducted the calculations, the amount of carbon dioxide has increased by 3% in the past five years alone, and 160% from pre-industrial levels. It is said that the rate of increase is faster than that of carbon. […] Nitrous oxide, the third largest anthropogenic greenhouse gas, increased by 1 part per billion last year to record levels, but the rate of increase was less than in 2020 and 2021. Nitrous oxide lasts about a century in the atmosphere. According to the EPA, it comes from agriculture, fuel combustion, fertilizers and industrial processes.
“Studies of specific isotopes of methane in the atmosphere show that much of the increased methane is due to microbial sources, indicating a sharp increase in emissions from wetlands and perhaps agriculture and landfills, but also Not as much as industry,” Lunn said.
