Related by context. Frequent words. (Click for all words.) 74 greenhouse gases 72 greenhouse gasses 70 greenhouse gas emissions 69 carbon dioxide emissions 69 greenhouse gas 66 carbon emissions 65 carbon dioxide 64 greenhouse emissions 63 CO2 emissions 62 carbon dioxide CO2 62 emissions 61 greenhouse gas emission 61 GHG emissions 60 CO2 60 carbon emission 56 heat trapping gases 56 reducing carbon emissions 56 global warming 55 emission reductions 55 mercury emissions 54 reduce carbon emissions 54 GHG 53 air pollution 53 pollutants 53 tailpipe emissions 53 emission reduction 52 carbon 52 NOx 52 nitrogen oxides 52 emission 52 nitrogen oxide 51 climate change 51 pollution 51 pollutant 50 fossil fuel 50 fossil fuels 50 burning fossil fuels 49 methane 49 Emissions 48 carbon footprint 48 ozone 48 gases 47 sulfur dioxide 47 particulate matter 46 Kyoto Protocol 46 acid rain 46 deforestation 46 smog 46 Carbon dioxide 45 mercury 45 reduce greenhouse gas 45 Kyoto protocol 45 gasses 45 water vapor 45 carbon footprints 44 nitrogen 44 renewable energy 44 reducing greenhouse gas 44 renewables 43 carbon offsets 43 ozone layer 43 emitters 42 coal fired 42 carbon sequestration 42 volatile organic compounds 42 VOCs 42 soot 42 polluting 42 particulates 41 carbon credits 41 carbon capture 41 toxic chemicals 41 biomass 41 biofuels 41 polluters 41 polluter 40 Global warming 40 aerosols 40 carbon neutral 40 environmental impacts 40 trans fats 40 phosphorus 40 phosphorous 40 tar sands 40 carcinogens 39 Copenhagen Accord 39 emitted 39 Renewable energy 39 biofuel 39 renewable 39 CO 39 renewable energies 38 emitting 38 Clean Air 38 renewable fuels 38 cleaner burning 38 energy 38 Climate Change 37 Global Warming 37 EPA 37 bio fuels