How much carbon was in the atmosphere when you were born?
I feel like I've been living under a rock. I had no idea people were saying (without saying) their birth year by comparing the levels of carbon in the atmosphere.
Driven by my curiosity, I found out that when someone writes they were born at a number followed by "ppm" (e.g. 335.41ppm), this means the level of carbon dioxide in the atmosphere ppm (part per million) during that year.
What is ppm - part per million? If you could divide the atmosphere into a million parts, that number (335.41, for example) out of the million parts would be made of carbon dioxide.
Last year (2025) the measured amount was up to 421ppm, the highest it has ever been. And it's increasing every year.
Who is measuring this? It seems some clever people at Mauna Loa Observatory - https://archive.govglance.org/data/mauna-loa-co2 keep an eye on the carbon levels, and have an extensive archive. Very interesting website too, worth a browse.
So what is your CO2 birth year? Mine may or may not be 335.41ppm. ;)