Probably someone has already reported the April number
403.26 ppm
Atmospheric CO2 for April 2015
preliminary monthly average
Mauna Loa Observatory (NOAA-ESRL data)
that there have recently (since 2011) been a significant acceleration in year to year increases even when the ENSO-signal is removed. I would love to have that graph updated by the way.
Ah, I've not done most anything on excel after I got most files saved from the laptop. There was some guesswork involved with that one, that I was not too sure about. 6 month delay on ENSO(CO2) and a year for biological response? Just now, I'm not too sure where I put those files trying to sort 4 different huge backups starting from c.2002...
(Modified ~hour afterwards)
found the file in question, maybe I'll get back to it sometime, but it shouldn't be too hard to replicate either.
(what was I thinking year ago?)
*Just remembering the biological carbon cycle is much larger than the anthropogenic one could give the 12 month delay involved here.
*That stock market values or indexes aren't reliable predictors of the rise of CO2 isn't at all surprising as they consist of many bubbles.
*Heat coming out of Pacific during El Nino effects almost all of tropics between 40N - 40S, so outgassing of CO2 is likely to happen with ~6 months delay like in the surface temperatures.