Year thousand metric tons of CO2 equivalent 1990 4726.2 1991 5523.4 1992 5988.7 1993 6432.8 1994 6191.6 1995 6974.1 1996 7439.2 1997 7891.9 1998 8805.7 1999 9554.6 2000 9925.7 2001 10546.3 2002 10954.4 2003 11609 2004 13998.7 2005 15114.9 2006 15616.2 2007 15886.5 2008 15512.8 2009 16740.1 2010 16784.3 2011 17166.9 2012 17246.1 2013 17300.1 2014 17187.2 2015 15594.7 2016 14343.9 2017 13746.3 2018 13775.7 2019 14023 2020 13241.4