I've been challenged to think of some really out-of-the-box ways to locate people, and I had one. I'm 90% sure this isn't reasonably possible (probably only in laboratory settings), but I couldn't find a real answer to this question, so now I'm genuinely curious.

It is possible to locate people's location by fluctuations in the Oxygen/Carbon Dioxide levels in the area (from people breathing)?

I realize this is a really general question, and would depend on a ton of factors (size of the area, number of people, proximity of people to an appropriate sensor, etc). I'm really just looking for a general answer, but in case it helps, I'm referring to a general case of detecting people in outdoor settings (it would be part of a sensor suite that is outdoors and just trying to count/locate people in the general area).

Even just a link to a technical paper that explains human impact on immediate area $\sf{O/CO_2}$ levels would be great - I've come up completely empty looking, everything I find just refers to global warming/overall environment/over thousands of years. Nothing for immediate impact, if there is any.

Edit: This was marked as off-topic? Seriously? This is 100% earth science.

  • $\begingroup$ Indoors, over minutes to hours? Yes. Outdoors? No. $\endgroup$
    – 410 gone
    Commented Apr 21, 2016 at 19:23
  • $\begingroup$ Common sense agrees, and knows this is likely a silly question, but I'd still like some real details and facts to back it up. Don't want to make assumptions. $\endgroup$ Commented Apr 21, 2016 at 19:25
  • $\begingroup$ My main worry would be plants since they "breathe in" CO2 and "breathe out" O2. $\endgroup$
    – user967
    Commented Apr 21, 2016 at 22:13
  • 2
    $\begingroup$ Mosquitoes do find you this way, so why not... $\endgroup$ Commented Apr 21, 2016 at 23:37
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    $\begingroup$ For what it's worth, this approach is used for detecting stowaways in containers, or otherwise for detecting (but not localising) people in enclosed environments. See armstrongmonitoring.com/store/shop/… for an example product. I'm doubtful as to whether it could be usefully applied outdoors, though. $\endgroup$ Commented Apr 22, 2016 at 13:16


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