Rowland Craig, a 57 year old male from San Antonio, Texas asks on January 5, 2004,

What is the volume of breathable air on the earth? Perhaps as one atmosphere?viewed 15217 times

I don't know about the 1 atmosphere part, but for a rough approximation you can easily work it out by calculating the volume of a sphere with radius of the Earth plus 5 kilometers (a height where most healthy people can still breathe). Then subtract the volume of the Earth from that. This would be pretty close, I imagine, for your purposes. The radius (r) of the Earth is about 6378km. The volume of a sphere is found by the formula 4/3 * pi * r^3 (four thirds pi times the radius cubed). Applying this formula to 6383 (i.e. 6378+5) we get 1089339226436 cubic kilometers. The volume of the Earth is 1086851326520 cubic kilometers. Subtracting these two numbers we find the volume of breathable air in cubic kilometers is 2,487,899,916, or about two and a half billion cubic kilometers of air. Quite a lot, eh?

Note: All submissions are moderated prior to posting.

If you found this answer useful, please consider making a small donation to science.ca.

- Canadian Nuclear Safety Commission Educational Resources
- National Inventors Hall of Fame
- JUMP Math
- Society for Canadian Women in Science and Technology
- SciQuest e-Solutions for Science
- Natural Sciences and Engineering Research Council of Canada
- Manning Awards for Innovation
- Royal Society of Canada
- Geological Survey of Canada
- Canadian Networks of Centres of Excellence
- Canadian Landscapes at Natural Resources Canada
- Canadian Association of Physicists
- A Century of Innovation
- Understanding Science
- AlphaGalileo
- National Film Board of Canada Youth Science
- PICS Climate Insights 101
- Canadian Association for Girls in Science
- Virtual Library for the History of Science
- The Chemical Institute of Canada
- Canadian Biotechnologist 2.0
- ISI Highly Cited Scientists
- Deep River Science Academy
- Journal of the History of Canadian Science
- Wikipedia
- Innovation Canada
- Engineering and Technology History Wiki
- Mars Society
- Nobel Prize Archive
- science.gc.ca
- Online Science Encyclopaedia by Astronomer David Darling
- CurioCity
- Canadian Nuclear FAQ
- Association of Science Communicators
- Astrofiles
- Wilderness Astronomy
- Ingenium
- The Geological Society online library