See the data version history.
The data of old versions are available only if the versions are included in Yearly fixed datasets.

 CO₂ _ BHD5012 _ surface - flask _ ESNZ _ data1

Updated Date	Version # : used for analysis in the WMO GHG Bulletin (#Volume) † met : with meteorological data	Details
2026-07-13	0057-5012-1001-01-02-9999 -2026-06-30-0231† met	The latest version