NOAA has published the latest N2O concentration.
March 2023: 336.58 ppb
March 2022: 335.42 ppb
March 2013: 325.7 ppb
Last updated: Jul 05, 2023
It is the highest concentration of nitrous oxide since humans live on this planet.
The annual increase of 1.16 ppb is significantly lower than last years, but still by 7% higher than the 10 y average (1.088 ppb/a).
I set an index = 100 to the average of 1980 [301.1 ppb]. March 2023 has a relative value of 111.8 compared to that index.