Year thousand metric tons of CO2 equivalent 1990 29001 1991 35111.6 1992 40670.3 1993 44172.4 1994 45340.1 1995 46925.9 1996 45376 1997 44650.2 1998 44624.3 1999 44884.3 2000 44050.1 2001 43977.1 2002 45609 2003 44023.2 2004 33913.6 2005 31871.2 2006 29940.1 2007 28739.9 2008 28271.3 2009 28555.6 2010 28444.7 2011 25775.2 2012 13949.5 2013 6327.5 2014 4526.4 2015 4322.6 2016 4163.6 2017 5730.6 2018 4446.9 2019 5529.9 2020 6080.1