Year thousand metric tons of CO2 equivalent 1990 0.9 1991 0.9 1992 0.9 1993 0.9 1994 0.9 1995 1 1996 1.4 1997 2.3 1998 2.2 1999 2.8 2000 4 2001 4.5 2002 6 2003 6.8 2004 8.4 2005 9 2006 9.7 2007 10.6 2008 10.8 2009 11.4 2010 11.8 2011 12.3 2012 12.8 2013 13.4 2014 13.8 2015 13.9 2016 14.5 2017 12.7 2018 12.2 2019 12.7 2020 11