I've found various figures quoted on websites, but really need a peer-reviewed source that I can quote! I appreciate that the answer will be dependent on the size of person, how active they are etc. I'm not thinking about "contributions to global warming" or anything like that, just the typical rate per person of CO2 breathed out in a day/year.
This link shows the per capita data on how much CO2 does the average person emits. you can even compare different countries against each other.
https://ourworldindata.org/co2/country/india#per-capita-how-much-co2-does-the-average-person-emit
https://ourworldindata.org/co2-emissions
Regards
Thanks Wati. That link is looking at pre-capita CO2 emissions from burning fossil fuels etc. What I'm interested in is simply (!) the air we breathe: When a person breathes, how much CO2 do they breathe out in total every day or every year? This will vary depending on activity - an active person will breathe more rapidly and deeply than an inactive person. So I'm looking for an average or a range.
The CO2 content of the exhaled air is about 4 %, thus 40 milliliters CO2 per liter air. However, oxygen consumption and thus CO2 emissions strongly depend on body size and physical activity. While around 4 liters of air per minute pass through the lungs at rest, it is over 50 liters per minute during physical exertion. For a whole year, these extremes mean about 170 kilograms of CO2 in periods of rest and more than 2,000 kilograms during continuous physical activity.
Alastair Howard i came across this question, this link may provide some solution
https://www.researchgate.net/post/How-much-will-be-the-human-breathing-CO2-emission-factor
Regards