Year thousand metric tons of CO2 equivalent 1990 19712.8 1991 18018.3 1992 16518.8 1993 15896 1994 14403.6 1995 14030.4 1996 14264.7 1997 13330.9 1998 12402.5 1999 12855.5 2000 12496.3 2001 12555.3 2002 12631.5 2003 12353.3 2004 12691.4 2005 12962.2 2006 12148.3 2007 12266.4 2008 11967.8 2009 10450.7 2010 11637.7 2011 10783.6 2012 10404.2 2013 10288.1 2014 9177.6 2015 8225.7 2016 8361.2 2017 8262.1 2018 8737.5 2019 8463 2020 8086.1