With the possibility of the coldest Super Bowl ever coming this week, this story about CO2 concentration seemed appropriate.
Ryan Scott Welch writes:
Anthony as you know, many people don’t know much about the earth’s atmosphere. For example, when questioned about how much CO2 is in our atmosphere most people give me a guess of somewhere between 30% and 70%. When I tell them that CO2 is only 0.04% or really about 395 ppm (parts per million) they generally look at me as if I was speaking some kind of foreign language. The layman simply cannot convert 0.04% of the atmosphere or 395 ppm into anything they can picture or relate to. In searching for some way to help the layman to understand the earth’s atmosphere, CO2, and the human contribution to atmospheric CO2, I came upon the idea of relating a sample of the atmosphere to something that nearly every person has seen, a football stadium.
So, instead of talking about ppm atmosphere, I talk about seats in a stadium. I put together a presentation using football stadium analogy and it goes something like this.
How much atmospheric CO2 is from human activity? If a football stadium represented a sample of our atmosphere, how many seats would be human caused CO2? The Dallas Cowboys Stadium seats 100,000 for special events.
Each seat represents one molecule of gas in our atmosphere.
Nitrogen is 78% of the atmosphere, Oxygen is 21%, and Argon is 0.9% giving you a total of 99.9% of the atmosphere.
So, where is the CO2? CO2 is a trace gas that is only 0.04% of the atmosphere which in this sample = 40 seats.
But of the 40 seats, or parts per 100,000 of CO2 in the atmosphere, 25 were already in the atmosphere before humans relied on hydrocarbon fuels (coal, gas and oil) leaving 15 seats.
And since humans only contribute 3% of all CO2 emitted into the atmosphere each year (97% is from nature), the human contribution is 3% of the 15 remaining seats in our sample. 3% of 15 is 0.45.
So in our stadium sample of 100,000 seats the human contribution of CO2 is less than half of one seat. That is less than one half of one seat from 100,000 seats in a Dallas Stadium sized sample of our atmosphere is human caused CO2.
[NOTE: per Dr. Robert Brown’s comment pointing out an oversight, this half-seat visualization analogy is on a PER YEAR basis, not a total basis – Anthony]
Here is my presentation uploaded on slideshare.net
Mauna Loa CO2 data: ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_mm_mlo.txt
Wigley, T.M.L., 1983 “The pre-industrial carbon dioxide level.” Climatic Change 5, 315-320 (lowest value of 250 ppm used)
Increasing Atmospheric CO2: Manmade…or Natural? January 21st, 2009 by Roy W. Spencer, Ph. D. http://www.drroyspencer.com/2009/01/increasing-atmospheric-co2-manmade%E2%80%A6or-natural/
Water Vapor Rules the Greenhouse System, Geocraft, http://www.geocraft.com/WVFossils/greenhouse_data.html
The Carbon Cycle, the Ocean, and the Iron Hypothesis, Figure based on Sabine et al 2004, Texas A&M University http://oceanworld.tamu.edu/resources/oceanography-book/carboncycle.htm