Related by context. Frequent words. (Click for all words.) 73 regulate greenhouse gases 63 regulate greenhouse gas 51 tailpipe emissions 48 greenhouse gases 48 heat trapping gases 48 burning fossil fuels 47 pollutant 45 global warming gases 45 GHGs 44 Clean Air 44 EPA 44 greenhouse gas 43 greenhouse gasses 43 mercury emissions 43 carbon dioxide 43 reduce greenhouse gas 43 Partial Birth Abortion Ban 41 greenhouse gas emissions 41 carbon dioxide emissions 41 roadless rule 41 mercury pollution 40 Environmental Protection Agency 40 emissions 40 global warming 40 greenhouse emissions 40 pollutants 39 Newdow 39 Endangered Species Act 39 combating global warming 39 gases blamed 38 reduce carbon emissions 38 overturn Roe v. Wade 38 greenhouse gas emission 38 reducing greenhouse gas 37 appellate court 37 rulemaking 37 reducing carbon emissions 37 emission 37 nitrogen oxide 36 secondhand smoke 36 Kyoto pact 36 appeals court 36 CAFE standards 36 emission reductions 36 phthalates 36 air pollution 36 cleaner burning 36 nitrogen oxides 36 GHG emissions 36 climate change 36 Kyoto treaty 35 polluters 35 suspend uranium enrichment 35 alternative fuels 35 EPA Administrator 35 MTBE 35 Sierra Club 35 secrets privilege 35 reducing CO2 emissions 35 emission reduction 35 tailpipe 35 carbon dioxide CO2 emissions 35 Clean Water Act 35 regulate 34 Kyoto Protocol 34 carbon emissions 34 9th Circuit 34 diesel exhaust 34 RGGI 34 Clear Skies 34 Carbon dioxide 34 justices 34 suspend enrichment 34 David Souter 34 fossil fuels 34 Toxic Substances 34 Justice Sonia Sotomayor 34 renewable fuels 34 pollution 34 judicial nominations 34 Average Fuel 33 halt uranium enrichment 33 Rehnquist 33 Supreme Court 33 coal fired 33 legally binding treaty 33 KDHE 33 prosecute 33 CO2 emissions 33 Kyoto accord 33 sulfur dioxide emissions 33 David H. Souter 33 ocean acidification 33 DOMA 33 acid rain 33 greenhouse gas GHG emissions 33 CO2 33 Emissions 33 CARB 33 GHG 33 sulfur dioxide