Related by context. Frequent words. (Click for all words.) 76 CO2 Emissions 75 Greenhouse Gases 75 Carbon Emissions 67 Greenhouse Gas 64 Emissions 64 Ethanol Production 63 GHG emissions 61 Fuel Efficiency 60 Fuel Costs 60 Reduce Emissions 60 greenhouse gas GHG emissions 60 Toxic Chemicals 60 GHGs 60 Fossil Fuels 59 greenhouse gas emissions 59 Commodity Prices 57 GHG 57 Gas Mileage 57 Fuel Consumption 57 Carbon Offsets 57 Carbon Offset 57 Carbon Footprint 57 Heating Costs 56 Cellulosic Ethanol 56 Carbon Dioxide 56 Traffic Congestion 56 GHG emission 56 greenhouse gas 56 Hidden Costs 55 Hybrid Cars 55 Offsets 55 Emission Reduction 55 Housing Slump 54 Ecological Footprint 54 Fuel Economy 54 Carbon Sequestration 54 greenhouse gasses 54 greenhouse emissions 54 greenhouse gas emission 54 Carbon Reduction 54 Budget Deficit 54 Slower Growth 54 Changing Climate 54 Coal Fired Power 54 Gasoline Prices 54 Proposed Changes 54 Improve Efficiency 53 Jobless Benefits 53 GHG reductions 53 greenhouse gases 53 Balanced Budget 53 Oil Spills 53 Jobless Claims Drop 53 GHG reduction 53 Jobless Claims Rise 53 Economic Optimism 53 Price Hikes 53 Storage Capacity 53 Jobless Claims Fall 52 Stronger Dollar 52 SO2 emissions 52 Climate Change 52 Flight Delays 52 Wholesale Prices 52 greenhouse gases GHGs 52 Hybrid Vehicles 52 CO2 emissions 52 Air Pollution 52 carbon emissions 52 Rate Increases 52 carbon dioxide emissions 52 Cell Phone Use 52 Costs Rise 52 Reporting Requirements 52 Budget Shortfall 51 Dollar Weakens 51 greenhouse gases GHG 51 Prices Drop 51 Cut Costs 51 Impacts 51 Million Tons 51 Prices Continue 51 Rulemaking 51 Record Levels 51 Longer Term 51 Oil Prices Slip 51 Economic Slowdown 51 Trans Fat 51 Cost Savings 51 Tax Hikes 51 Improve Quality 51 Ad Spending 51 Operational Efficiency 51 nitrous oxide emissions 51 Environmental Impact 51 Job Losses 51 emissions 51 Nuclear Reactors 51 Debt Limit 50 Beef Imports 50 Cost Reductions