Year thousand metric tons of CO2 equivalent 1990 248.6 1991 247.6 1992 261.7 1993 258.8 1994 252.7 1995 255.7 1996 291.5 1997 291.6 1998 292.2 1999 310.4 2000 324.5 2001 319.6 2002 324.8 2003 333.7 2004 345.1 2005 363.3 2006 361.7 2007 370.3 2008 354.8 2009 356.4 2010 390.2 2011 378.6 2012 394.9 2013 378.1 2014 399.1 2015 422.1 2016 463.8 2017 450 2018 435.5 2019 451 2020 426.5