******************************************************************** *** Atmospheric CO2-curve values (ppmv) derived from flask air *** *** samples collected at the South Pole *** *** *** *** Source: R. F. Keeling, S. C. Piper, A. F. Bollenbacher *** *** and S. J. Walker *** *** Carbon Dioxide Research Group *** *** Scripps Institution of Oceanography (SIO) *** *** University of California *** *** La Jolla, California USA 92093-0444 *** *** *** *** May 2008 *** ******************************************************************** Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann. Ave. 1957 313.88 314.33 314.62 314.70 314.64 314.51 1958 314.36 314.17 314.10 314.20 314.34 314.55 314.91 315.30 315.53 315.57 315.46 315.31 314.82 1959 315.13 314.92 314.84 314.92 315.06 315.27 315.65 316.06 316.33 316.41 316.38 316.31 315.61 1960 316.23 316.15 316.18 316.41 316.67 317.01 317.47 317.94 318.22 318.28 318.18 318.00 317.23 1961 317.78 317.53 317.40 317.44 317.54 317.71 318.02 318.37 318.55 318.53 318.37 318.16 317.95 1962 317.91 317.65 317.51 317.55 317.64 317.80 318.12 318.47 318.65 318.64 318.49 318.28 318.06 1963 318.05 317.80 317.67 317.72 317.83 318.01 318.34 318.71 318.91 318.92 318.78 318.60 318.28 1964 318.38 318.14 318.03 318.09 318.21 318.39 318.73 319.11 319.32 319.34 319.22 319.05 318.67 1965 318.86 318.65 318.57 318.67 318.84 319.08 319.49 319.95 320.25 320.36 320.34 320.26 319.44 1966 320.15 320.00 319.96 320.09 320.25 320.47 320.84 321.23 321.46 321.50 321.39 321.22 320.71 1967 321.03 320.81 320.70 320.77 320.89 321.07 321.40 321.77 321.98 321.99 321.87 321.71 321.33 1968 321.52 321.31 321.22 321.32 321.47 321.69 322.07 322.48 322.73 322.80 322.72 322.60 321.99 1969 322.45 322.28 322.23 322.37 322.56 322.82 323.23 323.68 323.96 324.04 323.98 323.86 323.12 1970 323.71 323.54 323.49 323.62 323.80 324.05 324.44 324.86 325.12 325.17 325.08 324.93 324.32 1971 324.75 324.54 324.44 324.52 324.65 324.85 325.20 325.58 325.79 325.82 325.71 325.55 325.12 1972 325.36 325.17 325.09 325.21 325.38 325.64 326.05 326.49 326.78 326.89 326.86 326.79 325.98 1973 326.70 326.59 326.60 326.80 327.05 327.36 327.81 328.29 328.58 328.66 328.58 328.43 327.62 1974 328.23 328.00 327.87 327.91 328.00 328.16 328.49 328.87 329.10 329.17 329.10 328.99 328.49 1975 328.86 328.70 328.66 328.78 328.95 329.19 329.59 330.03 330.31 330.40 330.34 330.22 329.50 1976 330.05 329.86 329.77 329.86 330.01 330.24 330.64 331.08 331.36 331.46 331.42 331.32 330.59 1977 331.19 331.04 331.01 331.17 331.39 331.68 332.12 332.61 332.94 333.08 333.08 333.02 332.03 1978 332.93 332.81 332.80 332.96 333.17 333.44 333.85 334.29 334.55 334.60 334.51 334.37 333.69 1979 334.21 334.03 333.99 334.14 334.35 334.65 335.11 335.61 335.95 336.11 336.13 336.09 335.03 1980 336.02 335.93 335.96 336.16 336.41 336.72 337.16 337.63 337.92 338.02 337.97 337.86 336.98 1981 337.72 337.54 337.48 337.59 337.75 337.98 338.35 338.76 339.00 339.06 338.99 338.87 338.26 1982 338.72 338.56 338.52 338.65 338.83 339.07 339.46 339.89 340.16 340.25 340.21 340.13 339.37 1983 340.05 339.97 340.01 340.25 340.53 340.89 341.37 341.88 342.21 342.33 342.30 342.19 341.17 1984 342.05 341.87 341.80 341.91 342.07 342.30 342.68 343.10 343.34 343.40 343.31 343.18 342.58 1985 343.02 342.86 342.82 342.97 343.18 343.48 343.93 344.41 344.73 344.84 344.82 344.74 343.82 1986 344.62 344.49 344.46 344.60 344.79 345.04 345.44 345.87 346.14 346.22 346.17 346.07 345.33 1987 345.96 345.84 345.85 346.04 346.30 346.64 347.12 347.65 348.01 348.17 348.20 348.16 347.00 1988 348.09 347.98 347.98 348.15 348.36 348.64 349.07 349.53 349.83 349.94 349.92 349.85 348.95 1989 349.75 349.62 349.60 349.75 349.94 350.19 350.59 351.01 351.26 351.32 351.24 351.12 350.45 1990 350.98 350.83 350.82 350.98 351.21 351.50 351.94 352.40 352.69 352.78 352.74 352.63 351.79 1991 352.50 352.35 352.31 352.44 352.62 352.87 353.26 353.68 353.93 353.99 353.91 353.79 353.14 1992 353.64 353.48 353.44 353.59 353.78 354.05 354.46 354.88 355.13 355.18 355.07 354.91 354.30 1993 354.71 354.49 354.40 354.48 354.63 354.85 355.23 355.64 355.90 355.96 355.89 355.76 355.16 1994 355.62 355.47 355.44 355.60 355.82 356.12 356.58 357.08 357.42 357.57 357.58 357.53 356.49 1995 357.45 357.34 357.34 357.50 357.72 358.01 358.44 358.92 359.25 359.40 359.41 359.37 358.35 1996 359.29 359.18 359.16 359.31 359.49 359.73 360.11 360.52 360.77 360.84 360.77 360.65 359.99 1997 360.50 360.34 360.28 360.40 360.57 360.82 361.22 361.68 362.00 362.15 362.20 362.22 361.20 1998 362.23 362.24 362.36 362.66 363.01 363.42 363.96 364.52 364.89 365.06 365.07 365.01 363.70 1999 364.91 364.78 364.75 364.89 365.07 365.33 365.73 366.18 366.48 366.60 366.59 366.52 365.65 2000 366.42 366.28 366.25 366.38 366.55 366.78 367.15 367.55 367.79 367.85 367.77 367.64 367.03 2001 367.49 367.32 367.28 367.43 367.65 367.95 368.41 368.92 369.28 369.46 369.50 369.49 368.35 2002 369.47 369.43 369.48 369.72 370.00 370.35 370.83 371.35 371.70 371.86 371.88 371.85 370.66 2003 371.81 371.73 371.76 371.97 372.21 372.52 372.96 373.43 373.74 373.86 373.85 373.79 372.80 2004 373.72 373.63 373.66 373.85 374.09 374.38 374.81 375.26 375.55 375.65 375.64 375.58 374.65 2005 375.52 375.45 375.50 375.73 376.02 376.37 376.85 377.36 377.70 377.85 377.85 377.80 376.67 2006 377.71 377.60 377.59 377.75 377.95 378.22 378.62 379.06 379.33 379.44 379.42 379.36 378.50 2007 379.29 379.22 379.26 379.48 379.76 380.10 380.58 381.09 381.44 381.60 381.64 381.62 380.42 Values above are taken from a curve consisting of 4 harmonics plus a stiff spline and a linear gain factor, fit to monthly concentration values adjusted to represent 2400 hours on the 15th day of each month. Data used to derive this curve are shown in the accompanying graph. Units are parts per million by volume (ppmv) expressed in the 2003A SIO manometric mole fraction scale. The "annual average" is the arithmetic mean of the twelve monthly values.