atmospheric co2 500kyr 

Atmospheric CO2 Data
Merged from serversal sources for the last 500.000 year (detail increases with more recent data)

merged from:
Macfarling Meure, C. et al., 2006: Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP. Geophysical Research Letters, 33.
http://scrippsco2.ucsd.edu/data/atmospheric_co2/icecore_merged_products
and:
EPICA Dome C Ice Core 800KYr Carbon Dioxide Data
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/epica_domec/edc-co2-2008.txt