Atmospheric Concentrations of Carbon Dioxide Source: Worldwatch Institute - http://www.worldwatch.org Year CO2 (ppm) 1764 276.7 1791 279.7 1816 283.8 1839 283.1 1843 287.4 1847 286.8 1854 288.2 1869 289.3 1874 289.5 1878 290.3 1887 292.3 1899 295.8 1903 294.8 1905 296.9 1909 299.2 1915 300.5 1921 301.6 1927 305.5 1935 306.6 1943 307.9 1953 312.7 1959 315.8 1960 316.8 1961 317.5 1962 318.3 1963 318.8 1964 318.5 1965 319.9 1966 321.2 1967 322 1968 322.8 1969 323.9 1970 325.3 1971 326.2 1972 327.3 1973 329.5 1974 330.1 1975 331 1976 332 1977 333.7 1978 335.3 1979 336.7 1980 338.5 1981 339.8 1982 341 1983 342.6 1984 344.3 1985 345.7 1986 347 1987 348.8 1988 351.4 1989 352.7 1990 354 1991 355.5 1992 356.2 1993 357 1994 358.8 1995 360.7