Year	thousand metric tons of CO2 equivalent
1970	4.738474
1971	3.737422
1972	3.612306
1973	3.578919
1974	2.9784955
1975	2.9109899
1976	2.2621258
1977	2.2680778
1978	2.4159664
1979	2.4473601
1980	2.3241351
1981	2.3200896
1982	2.1379088
1983	2.3233911
1984	2.3231834
1985	2.2547075
1986	2.2622529
1987	2.2518772
1988	2.3619272
1989	1.6216813
1990	1.2857157
1991	1.2229562
1992	1.2908214
1993	1.3598987
1994	1.3681416
1995	1.3720011
1996	1.3797945
1997	1.4012031
1998	1.409384
1999	1.4374297
2000	1.47498
2001	1.4876156
2002	1.550062
2003	1.5466179
2004	1.6062805
2005	1.6032518
2006	1.6315765
2007	1.6504834
2008	1.6615132
2009	1.6105337
2010	1.6428481
2011	1.659276581
2012	1.675705062