Do You Know Your Carbon Dioxide Birth Number?

I was talking with a group of students recently and asked what their carbon dioxide birth number was. In this article, I am posing the same question to you. The question was actually inspired by Toby Ray, a high school English teacher who recently followed me on Twitter. Often times, I browse the profile of new followers. His says, “Highschool English Teacher born at 330 ppm.” What is this all about anyhow?

I’ll define the carbon dioxide birth number (CO2BN) simply as the amount in parts per million (ppm) of carbon dioxide during the month that you were born. My CO2BN is 324.12 ppm. A baby born last month would have a CO2BN of 418.81 ppm. How do you find this number? I use the National Oceanic and Atmospheric Administration (NOAA) interactive website provided by the Global Monitoring Laboratory. By sliding along the carbon dioxide trend line on the graphic, month and amount is revealed.

The graphs above indicate the monthly average amount of carbon dioxide measured atop the Mauna Loa Observatory in Hawaii. At this location, scientists have the longest continuous dataset of direct measurements of carbon dioxide. According to NOAA’s website, “They were started by C. David Keeling of the Scripps Institution of Oceanography in March of 1958 at a facility of the National Oceanic and Atmospheric Administration.” The agency started its own measurement activity in the mid-1970s, and they have Benn taken simultaneously since that time. By the way, the term “ppm” can be interpreted in the following manner. My CO2BN of 324 ppm is actually 0.000324 (mole fraction). While a relatively small constituent in our atmosphere compared to nitrogen and oxygen, carbon dioxide definitely punches above its weight in our climate system.

Why was Mauna Loa (a volcano in the Pacific) chosen as the site of the “Keeling Curve” measurements? According to the NASA Earth Observatory website, “Isolated in the Pacific, it is far from major sources of pollution. Its high-altitude, lava-coated flanks are free of plants and trees, whose cycles of photosynthesis and respiration affect carbon dioxide concentrations.” The seasonal vegetation cycle is evident in the oscillating nature of the trend line. However, it is important to focus on the overall trend line rather than small segments of it to avoid cherry-picking. Scientists have such a good understanding of background amounts and are easily able to account for sporadic anomalies like a volcanic eruption.

Should we start putting our CO2BN on birth certificates or driver’s licenses? It is scary to think, on the current pathway, what my grandchildren’s number will be. In fact, that very concern motivates me everyday as an atmospheric scientist. Even as I write this, some child is receiving a carbon dioxide birth number today.