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?

By: Ryan Scott Welch

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%, Argon is .9% giving you a total of 99.9% of the atmosphere

Nitrogen OxygenArgon Trace gassses

So, where is the CO2?

CO2 is a trace gas that is only 0.04% of the atmosphere which in this sample = 40 seats.

Nitrogen OxygenArgon Trace gassses

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.

40 Seat Section

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

40 Seat Section

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.

Non-Human CO2 Human CO2

40 Seat Section

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.

One single seat

Non-human CO2Human CO2

Less than half of one single seat is a human caused CO2 molecule. Did you know that?

Current atmospheric measurement of CO2 from the Mauna Loa Observatory.

Source data: ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt

Reference Page

Climatic Change1983, Volume 5, Issue 4, pp 315-320The pre-industrial carbon dioxide levelT. M. L. Wigley

Recent indirect data and direct measurements from ice cores point towards a ‘pre-industrial’ CO2 level of around 260–270 ppmv, considerably below the commonly assumed value of 290 ppmv. Early measurements from the southern hemisphere tend to favor the lower value.

Note: I use the lowest number of 250 ppmv.

Reference Page

Human contribution to CO2 http://www.drroyspencer.com/2009/01/in

creasing-atmospheric-co2-manmade%E2%80%A6or-natural/

http://www.geocraft.com/WVFossils/greenhouse_data.html

http://stevengoddard.wordpress.com/2011/02/08/evil-oceans-produce-16-times-as-much-co2-as-humans/

Reference Page