********************************************************************* *** 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 1985 -99.99 -99.99 -99.99 -99.99 349.85 348.65 346.97 344.51 342.17 343.22 345.61 346.64 -99.99 1986 348.17 349.46 349.66 350.33 351.24 350.28 348.17 344.68 342.62 344.80 347.58 348.98 348.00 1987 350.34 350.88 351.58 353.25 353.50 351.94 349.36 345.49 344.53 347.15 349.41 350.90 349.86 1988 352.83 353.87 353.94 354.98 355.76 355.05 353.19 350.56 349.52 350.86 352.01 353.03 352.97 1989 354.54 355.23 356.04 357.78 357.68 356.33 353.23 348.58 348.99 352.27 353.91 355.85 354.20 1990 356.56 356.77 357.67 358.81 358.54 356.63 353.92 350.92 350.44 352.39 354.26 355.64 355.21 1991 357.22 358.67 359.00 360.35 361.04 358.61 355.93 353.77 352.66 354.50 356.34 357.30 357.12 1992 358.35 359.22 359.85 360.58 360.69 358.19 355.64 353.24 351.96 353.10 355.01 356.88 356.89 1993 358.42 359.13 359.39 360.85 361.67 359.18 356.91 354.37 352.48 354.62 357.10 358.16 357.69 1994 359.39 360.54 361.31 362.59 363.40 361.06 358.12 356.14 354.73 356.08 358.06 359.22 359.22 1995 361.02 361.61 362.13 363.92 364.46 362.78 360.03 357.48 356.53 358.35 360.75 361.95 360.92 1996 363.56 364.96 365.62 365.98 366.08 364.86 362.73 359.70 356.91 358.93 361.72 363.49 362.88 1997 365.09 365.35 366.30 367.94 367.72 365.26 362.53 360.04 358.59 360.95 363.80 365.80 364.11 1998 366.64 366.65 367.59 369.59 370.30 367.24 364.06 364.02 363.45 364.39 367.07 368.34 366.61 1999 368.47 368.19 369.52 371.94 372.26 370.53 367.79 364.59 364.00 365.39 367.27 369.28 368.27 2000 370.25 370.24 370.88 372.09 372.28 370.94 368.77 366.72 365.71 366.88 369.18 370.51 369.54 2001 372.25 372.99 373.24 374.53 374.66 372.51 370.25 368.33 366.88 368.51 371.35 372.21 371.48 2002 373.18 373.72 374.45 375.94 376.39 375.40 372.67 369.00 368.05 371.13 373.85 375.16 373.25 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.