I am working on the global CO2 emission using a model dataset. The model provides the CO2 emission in mol m-2 s-1. How to convert mol m-2 s-1 CO2 emission to Megaton day-1 (Mt per day)?


  • $\begingroup$ You don't have enough information. You have a flux rate, so without a defined area, you can't convert to daily emissions. You can easily convert moles to Mt, and seconds to days, but you still need an area defined. $\endgroup$
    – f.thorpe
    May 4 at 14:22
  • $\begingroup$ Thank you sir, your answer solved the problem. There was a global dataset, and the area was 510.1 million km². $\endgroup$ May 4 at 14:52

Do the calculation for 1 mol of CO$_2$

1 mol of CO$_2$ weighs 49 grammes = 0.0049 kg

86400 seconds in a day, so 864000 * 0.0049 = 423.36 kg/day/m$^2$

The surface area of the globe is 5.1 x 10$^{14}$ m$^2$ - so 423.6 * 5.1 x 10$^{14}$ = 2.16 x 10$^{17}$ kg/day

Convert from kg to Megatons, 10$^9$ kg in a Megaton - so we get 1 mol CO$_2$/m$^2$/second = 2.16 x 10$^8$ Megatons/day

This assumes, as farrenthorpe commented, that the molar emission rate represents a rate evenly distributed over the globe - if, for instance it only represented terrestrial emissions, or emissions in a particular region the calculation would need to take that into account.

  • $\begingroup$ Thank you sir for explaining in detail. It helped out. $\endgroup$ May 4 at 14:55
  • $\begingroup$ Farhan - happy to help out. I just edited my answer as I had made an error in units that changed the answer. I missed conversion from square metres to square kilometres! $\endgroup$
    – Andy M
    May 4 at 15:57

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.