Year thousand metric tons of CO2 equivalent 1970 12284.488726561991 1971 9389.21587499998 1972 20480.07334375001 1973 10112.631906250019 1974 13474.21851562499 1975 18236.842867186984 1976 28145.40549218704 1977 28655.865460937013 1978 18386.20462500002 1979 29319.410945312004 1980 33960.19846875002 1981 17566.61196875001 1982 29812.332625000003 1983 18980.262062500027 1984 21024.221617186973 1985 36588.764078124965 1986 27892.564414061984 1987 9421.270890625012 1988 20981.740757811996 1989 23024.18549999997 1990 -6368.110351563024 1991 -7277.887695313024 1992 -7024.25 1993 -7833.637695313024 1994 -9208.109375 1995 -9568.018554688024 1996 -8971.48828125 1997 -11488.48046875 1998 -10248.73828125 1999 -14568.708984375 2000 -14652.552734375 2001 -19953.369140625 2002 -22264.91015625 2003 -31996.65625 2004 -33870.814453125 2005 -33892.5390625 2006 -25249.10546875 2007 -34203.037109375 2008 -32988.638671875 2009 -31081.380859375 2010 -21765.140625 2011 -30485.052734375 2012 -20663.681640625 2013 -22742.505859375 2014 -22586.552734375 2015 -29898.16015625 2016 -17268.705078125