Related by context. Frequent words. (Click for all words.) 87 emissions 79 carbon emission 76 greenhouse gas emission 74 emission reduction 73 Emission 73 greenhouse gas emissions 71 greenhouse gas 71 carbon dioxide emissions 71 carbon emissions 71 Emissions 70 emission reductions 69 greenhouse emissions 69 CO2 emissions 69 tailpipe emissions 68 NOx 68 exhaust emissions 67 greenhouse gases 67 GHG emissions 67 pollution 66 carbon 66 CO2 65 GHG 64 air pollution 61 greenhouse gasses 61 emitters 60 nitrogen oxide 60 mercury emissions 60 emitting 58 pollutant 58 sulfur dioxide emissions 57 global warming gases 57 carbon dioxide 56 reduce carbon emissions 56 nitrogen oxides 55 carbon dioxide CO2 54 heat trapping gases 54 CARB 54 reducing carbon emissions 54 mercury pollution 53 polluting 53 polluters 53 zero emission 53 emit 53 particulate matter 53 pollutants 52 sulfur dioxide 51 polluter 51 ozone 51 diesel exhaust 50 polluting industries 50 smog 50 particulates 50 particulate 49 diesel engines 49 carbon credits 49 emitted 49 VOC 49 coal fired 49 EPA 49 gases 48 Pollution 48 VOCs 48 soot 48 Kyoto Protocol 48 diesel 47 Kyoto accord 47 Clean Air 47 combustion 46 emitter 46 Kyoto 46 Air Quality 45 volatile organic compounds 45 diesels 45 renewable energy 45 diesel powered 45 Kyoto protocol 45 renewables 44 methane 44 EVs 44 carbon capture 44 cleaner burning 44 fossil fuel 44 pollute 44 sulfur 43 global warming 43 Carbon 43 Environmental Protection Agency 43 acid rain 43 tailpipe 43 Air Pollution Control 43 CDM 43 climate change 42 RGGI 42 ETS 42 g km 42 atmospheric carbon dioxide 42 diesel engine 42 carbon offsets 42 hydrogen 42 gasses 42 regulate greenhouse gases