Thanks for the explanation.I suggest the UNEP report, think that has them (Check annexed) NAOA has daily measurements every day and plots etc. (Must be nearly 20 years worth by now) that’s only one location of course,
like any single measure that has issues. National labs around the world also have daily measurements on line.
but, Cos CO2 isn’t evenly distributed in ambient air globally, getting a single number for a year per-see is a tricky job - and a bit meaningless - RF feedbacks work differently in different locations due to a lot of factors. Optical depth, air quality, baseline atmosphere metrics, lapse rates etc etc Not least the simple ppm measure to show any effect of COVID has large problems because it doesn’t account for natural fluctuations- there were an epic number of huge forest fires last year for eg - what proportion of any change was COVID or other factors...
probably a better measure, if after a crude indicator, woukd be looking at energy consumption globally- there are relatively good metrics for that. although they don’t account for efficiency differentials. Which is important. take the UK as a metric for an Example. Less energy may have been used for cars etc but the energy used may not have been used in ways that emit fewer emissions. Home working in the housing stock we have, with really terrible standards, are much worse than modern offices/builds. we may all even have sat at home in blankets trying to leave the heating off for as long as possible to save a few quid while on furlough, but that doesn’t mean it’s had less impact on concentrations.
I think it proves my point.