ghg emissions_2009_million_tonnes emissions_1990_million_tonnes emissions_1950_million_tonnes
CO2 1.76 1.288732214 0.594955859
CH4 0.502 0.470354525 0.235243101
N2O 0.172 0.129200535 0.064408219
PFC,HFC,SF6 0.015 0.0111088 0
Montreal gasses 0.26 0.229976021 0