This data set provides a new CO2 record from the Siple Dome ice core, Antarctica, that covers 7.4-9.0 ka (thousand years) with 8- to 16-year resolution. A small, about 1-2 ppm, increase of atmospheric CO2 during the 8.2 ka event was observed. The increase is not significant when compared to other centennial variations in the Holocene that are not linked to large temperature changes. The results do not agree with leaf stomata records that suggest a CO2 decrease of up to ~25 ppm and imply that the sensitivity of atmospheric CO2 to the primarily northern hemisphere cooling of the 8.2 ka event was limited.