********************************************************************* *** 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 -99.99 -99.99 -99.99 -99.99 339.26 -99.99 1980 340.27 341.72 342.30 342.13 341.80 340.69 337.76 334.48 333.72 335.88 338.67 340.09 339.13 1981 340.43 341.99 343.66 344.20 343.48 340.27 336.79 334.48 333.93 336.23 338.60 340.68 339.56 1982 342.03 343.22 345.03 346.01 344.82 341.93 336.09 332.25 334.76 339.17 343.16 344.53 341.08 1983 345.10 345.45 344.88 345.45 345.29 343.67 341.78 338.64 337.33 339.84 343.31 344.80 342.96 1984 346.49 348.05 347.48 346.82 347.80 345.27 340.96 339.07 339.22 341.44 344.60 346.48 344.47 1985 346.66 347.85 350.22 350.69 348.70 345.93 341.81 338.50 340.54 345.19 347.88 349.19 346.10 1986 349.77 349.18 349.44 350.81 350.66 350.11 348.25 345.67 345.28 346.98 348.87 348.90 348.66 1987 348.48 349.68 352.00 353.15 351.05 348.66 347.46 344.40 342.53 345.97 349.28 350.76 348.62 1988 352.24 353.08 353.17 354.06 353.34 351.55 350.19 347.93 346.56 349.25 352.95 354.58 351.58 1989 354.38 354.83 357.31 357.58 355.87 353.27 -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 -99.99 352.89 356.59 358.07 -99.99 1991 357.99 358.03 359.97 361.16 359.34 358.61 355.42 350.43 350.35 352.50 353.77 354.60 356.01 1992 357.87 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 -99.99 1993 -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 1994 -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 1995 360.70 361.49 362.41 363.03 363.38 361.41 356.34 353.23 354.65 358.26 361.48 363.11 359.96 1996 363.47 363.99 365.05 366.09 366.00 365.59 364.13 360.20 358.17 359.73 361.80 363.94 363.18 1997 365.18 365.01 365.20 366.27 366.67 364.87 361.28 356.94 356.43 359.95 364.49 367.10 363.28 1998 366.59 365.43 366.81 368.86 368.32 366.37 363.40 359.78 360.76 364.65 367.58 369.23 365.65 1999 370.56 370.97 371.11 371.48 372.02 370.59 366.70 364.23 364.59 366.79 368.36 369.49 368.91 2000 370.74 370.63 371.57 373.70 373.21 370.08 367.62 366.76 365.67 366.90 369.91 372.09 369.91 2001 372.57 372.66 374.16 376.05 374.42 371.59 370.19 367.74 366.44 368.94 371.01 372.58 371.53 2002 374.41 375.76 376.50 376.46 376.44 373.98 370.75 370.20 369.93 370.71 373.36 375.20 373.64 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.