********************************************************************* *** 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 1983 339.89 339.95 340.05 340.33 340.95 341.34 341.55 342.27 342.87 342.65 342.31 342.11 341.36 1984 341.92 341.73 341.61 341.82 342.25 342.50 342.70 342.98 343.34 343.78 343.83 343.47 342.66 1985 343.09 343.14 343.73 344.16 344.03 343.86 343.95 344.53 345.00 345.12 345.23 345.17 344.25 1986 344.75 344.45 344.33 344.42 344.70 345.06 345.49 345.73 345.97 346.26 346.30 345.98 345.29 1987 346.00 346.57 346.60 346.24 346.42 347.00 347.62 347.97 348.32 348.75 348.99 348.77 347.44 1988 348.56 348.95 349.06 348.93 349.28 349.76 350.08 350.38 350.56 350.45 -99.99 -99.99 -99.99 1989 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 1990 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 1991 352.13 352.15 352.51 352.99 353.17 353.14 353.46 353.90 354.07 354.13 353.95 353.59 353.27 1992 353.24 352.95 352.92 353.77 355.06 355.54 355.25 355.06 355.36 355.64 355.40 354.98 354.60 1993 354.74 354.46 354.30 354.47 354.69 354.94 355.33 355.69 356.01 356.31 356.37 356.09 355.28 1994 355.77 355.71 355.70 355.65 355.77 356.15 356.69 357.26 358.03 358.47 358.14 357.67 356.75 1995 357.60 357.61 357.36 357.32 357.60 358.15 358.59 358.68 358.86 358.84 358.61 358.52 358.15 1996 358.52 358.63 358.60 358.62 358.91 359.33 359.71 360.02 360.30 360.41 360.35 360.45 359.49 1997 360.43 360.24 360.33 360.52 360.62 360.80 361.05 361.34 361.53 361.68 361.60 361.40 360.96 1998 361.58 361.92 362.05 362.33 362.87 363.33 363.81 364.35 364.65 364.81 364.95 364.95 363.47 1999 364.92 364.91 364.96 365.11 365.22 365.39 365.74 366.13 366.37 366.38 366.39 366.20 365.64 2000 365.85 365.88 366.05 366.18 366.26 366.42 366.85 367.28 367.48 367.63 367.68 367.50 366.76 2001 367.27 367.22 367.38 367.69 367.95 368.27 368.82 369.33 369.70 369.97 370.08 369.80 368.62 2002 369.29 369.16 369.41 369.63 369.86 370.29 370.80 371.34 371.75 371.89 371.92 371.80 370.60 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.