Year	thousand metric tons of CO2 equivalent
1970	2.2563381
1971	2.257327
1972	2.0875462
1973	2.1438577
1974	2.096778
1975	2.2827904
1976	2.3307009
1977	2.1990718
1978	2.1575907
1979	2.6801453
1980	3.16479
1981	2.6609594
1982	2.9726303
1983	2.9490486
1984	2.9103265
1985	3.039581
1986	3.347845
1987	3.34831
1988	4.323291
1989	4.429652
1990	4.629881
1991	5.697397
1992	6.59339
1993	6.749599
1994	7.324277
1995	7.375892
1996	7.36281
1997	7.618777
1998	7.911696
1999	8.168221
2000	8.383485
2001	8.467495
2002	8.642645
2003	8.999269
2004	9.006926
2005	9.305084
2006	9.69153
2007	9.95875
2008	9.550945
2009	9.916373
2010	10.436832
2011	10.54120032
2012	10.64556864