This page of data links was started to help you find the source dataset you are looking for.
CO2 Data | Years 0 to 2014
Datasets are compiled by the Institute for Atmospheric and Climate Science (IAC) at Eidgenössische Technische Hochschule in Zürich, Switzerland.
IAC Switzerland Global CO2 Yearly [excel]
IAC Switzerland Global CO2 Monthly [excel]
CO2 Data Pages
Scripps UCSD Mauna Loa CO2 Data + Primary Mauna Loa CO2
NOAA-ESRL Trends in CO2 + CO2 Data
CO2.earth Yearly CO2 + Monthly CO2 + Daily CO2
More Data and Info
NOAA-NCDC Ice core datasets at the World Data Center
NOAA-NCDC Paleoclimate datasets
NOAA-NCDC Climate data online (including recent data)