********************************************************************* *** Atmospheric Carbon Dioxide Mixing Ratios from the *** *** NOAA CMDL Carbon Cycle Cooperative Global Air Sampling *** *** Network, 1968-2002 *** *** *** *** March 2005 *** *** *** *** Source: Thomas J. Conway *** *** Pieter P. Tans *** *** NOAA Climate Monitoring and Diagnostics Laboratory *** *** 325 Broadway *** *** Boulder, Colorado, U.S.A. *** ********************************************************************* Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann 1989 -99.99 -99.99 -99.99 -99.99 357.46 354.23 350.88 349.76 351.16 351.97 352.97 354.88 -99.99 1990 355.61 356.58 357.95 359.17 358.66 354.60 352.46 351.59 349.94 352.91 356.33 356.13 355.16 1991 357.47 358.33 359.89 361.63 360.10 358.14 356.47 350.93 349.57 355.05 356.53 357.23 356.78 1992 359.39 360.04 360.78 360.24 358.93 358.72 356.24 348.92 347.37 353.12 355.87 356.86 356.37 1993 359.44 361.25 360.19 359.86 358.67 356.22 355.75 353.85 353.23 355.57 356.63 358.21 357.41 1994 360.27 361.24 362.33 363.12 362.33 360.26 358.30 355.98 354.58 357.72 360.49 361.19 359.82 1995 362.75 363.48 363.92 364.32 363.62 361.89 358.53 355.32 355.40 358.97 361.47 362.32 361.00 1996 363.87 364.67 365.25 366.52 365.27 363.90 363.06 359.84 357.80 360.36 362.62 364.02 363.10 1997 365.44 365.32 366.63 368.27 367.10 365.78 365.02 360.90 358.19 361.72 365.96 366.22 364.71 1998 366.50 368.86 370.11 369.61 368.38 366.82 365.40 361.99 360.13 363.38 367.25 368.30 366.39 1999 369.18 371.24 372.15 371.89 370.31 369.43 368.11 363.98 361.83 365.22 369.48 370.60 368.62 2000 372.05 373.60 373.48 373.45 372.61 370.78 368.11 364.92 364.30 367.81 371.64 372.31 370.42 2001 372.73 374.39 375.49 375.84 374.31 371.10 369.95 368.34 366.37 369.46 371.05 372.64 371.81 2002 375.02 374.29 374.33 375.72 375.33 374.01 372.95 370.44 368.99 370.05 370.96 372.97 372.92 Monthly measurements are reported in parts per million (ppm) and are directly traceable to the WMO CO2 mole fraction scale. Annual values are the arithmetic means of the 12 monthly values.