********************************************************************* *** 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 1979 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 337.43 337.31 337.26 337.84 338.41 -99.99 1980 338.27 337.95 337.91 338.36 338.77 339.39 339.68 339.67 339.39 338.99 338.74 338.80 338.83 1981 339.10 338.92 339.26 339.57 339.04 339.13 340.27 340.90 340.66 340.44 340.25 339.79 339.78 1982 339.70 339.72 339.76 340.47 340.85 340.58 340.68 341.18 341.19 341.13 340.86 340.63 340.56 1983 341.34 341.82 341.59 341.74 342.45 343.37 343.45 343.17 343.19 343.34 343.22 343.29 342.66 1984 343.29 342.57 342.44 342.74 343.24 344.02 345.07 345.22 344.29 344.55 344.97 344.21 343.88 1985 343.72 343.83 344.23 344.08 344.18 345.46 346.06 345.75 345.80 346.29 346.23 346.06 345.14 1986 345.87 345.06 344.34 344.81 345.62 346.21 347.05 347.40 346.98 346.78 346.94 346.69 346.15 1987 346.52 346.65 346.82 347.07 348.07 349.08 349.31 349.59 349.43 349.23 349.55 349.49 348.40 1988 349.24 349.36 349.30 349.10 349.58 350.81 351.50 351.29 351.17 351.14 351.21 351.35 350.42 1989 351.41 351.31 350.67 350.76 351.27 351.68 352.32 352.55 352.37 352.17 352.05 351.94 351.71 1990 351.94 351.77 351.29 351.90 352.79 353.12 353.78 354.35 354.11 354.01 353.95 353.47 353.04 1991 353.47 353.55 352.99 352.58 353.24 354.05 354.52 354.78 354.58 354.83 354.96 354.58 354.01 1992 354.32 354.20 354.12 354.62 355.26 355.59 356.19 356.24 355.95 355.92 355.74 355.30 355.29 1993 354.94 354.74 354.62 354.77 355.14 356.05 356.27 356.35 357.38 357.55 356.76 356.34 355.91 1994 356.58 356.09 355.15 355.73 356.73 357.31 358.23 358.60 358.27 358.28 358.47 358.59 357.34 1995 358.66 358.33 357.83 357.76 358.37 359.22 359.96 360.21 360.21 360.23 360.33 360.49 359.30 1996 360.31 359.84 358.76 358.44 359.86 361.03 361.14 361.12 361.24 361.31 361.42 361.53 360.50 1997 361.38 360.90 360.78 360.81 361.00 362.12 362.84 362.74 362.71 363.49 363.83 363.34 362.16 1998 363.09 363.21 363.12 363.21 364.76 366.11 365.84 365.91 366.37 366.22 366.31 366.04 365.02 1999 365.39 365.02 364.71 364.73 365.58 366.50 367.26 367.50 367.34 367.42 367.60 367.54 366.38 2000 367.33 367.11 366.41 366.12 367.42 368.33 368.72 368.61 368.32 368.70 368.71 368.21 367.83 2001 368.03 368.26 368.37 368.43 369.17 -99.99 -99.99 -99.99 370.45 370.85 370.70 370.21 -99.99 2002 370.22 370.34 369.77 370.20 371.33 371.99 372.57 372.81 372.78 372.90 373.00 373.07 371.75 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.