2014
2004
1994
1984
300
325
350
375
400
CO2 parts per million
2014
2004
1994
1984
300
325
350
375
400
CO2 parts per million
2014
2004
1994
1984
300
325
350
375
400
CO2 parts per million
2014
2004
1994
1984
300
325
350
375
400
CO2 parts per million