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Growth rate of atmospheric CO2 and CH4 based on ice core measurements of Etheridge et al. (20, 21), in situ CO2 observations initiated by C. D. Keeling (11), and National Oceanic and Atmospheric Administration (NOAA) CO2 and CH4 observations made available by the NOAA Climate Monitoring and Diagnostics Laboratory (ftp://ftp.cmdl.noaa.gov/ccg).
