Related by context. Frequent words. (Click for all words.) 57 carbon dioxide emission 56 CO2 emission 54 GHG emission 54 CO2 emissions 54 CO ² 53 Co2 53 carbon emission 53 CO2 Emissions 52 emission 52 GHGs 51 pollutant emissions 51 CO2 50 nitrous oxides 49 reducing CO2 emissions 49 SO2 emissions 49 sulfur dioxide SO2 49 C# emissions 49 NOx emissions 49 carbon dioxide emissions 49 exhaust emissions 48 emissions 48 Carbon Emissions 48 CO2e 48 CO2 emitted 48 greenhouse gas emission 48 carbon emissions 48 sulfur fuels 48 greenhouse gas GHG emissions 48 Bioethanol 48 exhaust emission 47 GHG emissions 47 HCFC 47 greenhouse gas emission reductions 47 particulate matter PM 46 sulfur oxide 46 greenhouse emissions 46 SOx 46 greenhouse gas emissions 46 Emissions 46 greenhouse gasses 46 carbon emission reductions 46 Greenhouse Gas Emissions 46 particulate emissions 46 sulfur dioxide nitrogen oxides 46 Emissions Trading Scheme ETS 45 consumptions 45 NOx 45 greenhouse gas 45 nitrogen oxides NOx 45 reduce carbon emissions 45 GHG reduction 45 GHG 45 SO2 44 particulate matter emissions 44 emitting greenhouse gases 44 pollution 44 carbon dioxide CO2 emissions 44 Greenhouse Gases 44 nitrous oxide emissions 44 carbon emitted 44 emission reductions 44 emission reduction 44 Carbon dioxide emissions 44 reducing carbon emissions 43 greenhouses gases 43 polluting 43 carbon emitting 43 polluter pays 43 greenhouse gases 43 greenhouse gas GHG 43 Emission 43 emitting carbon dioxide 43 distortionary 43 carbon dioxide CO2 42 Polluting 42 bio ethanol 42 NO2 42 mechanism CDM 42 diesel 42 carbon 42 nitrogen oxide emissions 42 fossil fuel 42 #g/km [001] 42 N2O 42 nitrogen oxide NOx 42 VOC emissions 42 emit carbon dioxide 42 polluter pays principle 42 landfilling 41 ozone depleting substances 41 Greenhouse gases 41 legally binding emission 41 Carbon Dioxide 41 pollutions 41 ratified Kyoto 41 carbon dioxide 41 CFCs 41 hydrofluorocarbons 41 particulate filters 41 ZEV 41 Greenhouse Gas