********************************************************************* *** 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 1981 -99.99 -99.99 345.44 345.60 346.38 344.81 337.45 332.84 335.04 339.34 342.74 344.02 -99.99 1982 344.48 345.34 345.91 345.73 345.53 344.51 338.57 332.14 333.08 338.15 341.94 344.31 341.64 1983 345.11 345.41 346.87 347.37 346.33 344.21 338.58 333.90 335.45 340.53 343.59 345.91 342.77 1984 347.55 348.11 349.11 349.49 347.94 345.32 340.22 336.02 338.94 342.77 345.00 347.11 344.80 1985 348.43 349.27 350.61 351.53 351.02 347.56 341.43 336.78 338.06 342.48 346.57 349.35 346.09 1986 350.88 351.21 352.42 353.25 351.73 348.58 343.91 338.86 339.13 344.00 348.51 350.54 347.75 1987 351.48 352.73 353.51 353.48 352.70 350.35 345.32 340.53 340.67 345.43 350.14 352.17 349.04 1988 354.38 355.79 355.88 356.53 356.02 353.95 348.28 343.15 344.94 349.96 353.60 355.51 352.33 1989 356.53 357.16 357.90 358.51 358.11 355.93 350.28 345.29 346.27 351.14 354.91 357.02 354.09 1990 358.32 359.34 359.89 359.83 358.95 355.33 349.02 345.47 347.39 352.08 355.16 357.43 354.85 1991 359.33 360.77 361.33 361.05 360.62 357.77 352.11 348.06 349.24 353.10 356.94 359.07 356.62 1992 359.69 360.39 361.92 362.52 361.27 358.26 352.72 347.00 347.86 352.47 356.81 359.12 356.67 1993 360.01 361.17 362.45 362.80 362.64 359.75 352.91 347.63 349.09 353.86 358.72 361.87 357.74 1994 362.56 362.86 363.84 363.78 362.64 360.18 354.41 349.36 350.75 356.74 360.86 362.34 359.19 1995 363.38 364.31 365.48 365.68 364.27 361.52 356.40 351.96 352.58 357.44 361.78 364.51 360.78 1996 366.28 366.04 366.81 368.06 366.95 365.15 360.46 354.09 355.92 362.37 364.22 364.60 363.41 1997 366.21 367.79 368.54 368.45 367.82 365.16 358.90 354.19 356.02 361.32 365.57 368.94 364.08 1998 369.78 369.56 369.75 369.73 370.12 368.40 362.34 357.90 360.10 364.83 368.00 370.54 366.75 1999 372.73 373.32 373.68 373.87 372.69 369.61 363.87 359.19 362.02 366.36 368.99 371.71 369.00 2000 373.13 373.93 374.64 374.28 373.60 371.68 366.36 360.84 362.92 369.43 373.19 374.77 370.73 2001 376.27 376.53 376.49 376.65 375.87 372.91 366.62 361.31 362.90 368.75 372.56 374.52 371.78 2002 376.26 377.45 377.82 377.34 376.10 373.67 368.24 363.37 364.63 370.34 375.47 378.32 373.25 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.