Year kt of CO2 equivalent 1970 42.3062976 1971 42.7869478 1972 43.2866131 1973 43.7245901 1974 44.130957 1975 44.4819076 1976 131.6337457 1977 135.0553194 1978 358.990001 1979 409.505485 1980 424.783771 1981 519.001013 1982 564.023574 1983 530.385687 1984 571.038292 1985 642.147964 1986 435.85886 1987 616.928696