Related by context. Frequent words. (Click for all words.) 65 finite resource 64 nonrenewable resources 51 Fossil fuels 49 fossil fuels 49 aquifers 48 nonrenewable 47 underground aquifer 47 underground aquifers 47 fossil fuel 46 Arctic Refuge 45 bauxite ore 45 byproducts 45 aquifer 45 seabeds 45 precious 44 Conserving 44 tar sands 44 finite 44 Fossil Fuels 44 Alberta tar sands 44 petroleum 44 natural gas 43 oil 43 contaminate groundwater 43 fragile ecology 43 technically recoverable 43 aquifer recharge 43 Ogallala Aquifer 43 carbon dioxide sequestration 43 irrigated agriculture 43 groundwater basin 43 kerogen 43 despoiled 42 pollutes 42 extractive 42 liquid fuels 42 vast quantities 42 Ecologically 42 streambeds 42 liquified 42 shale deposits 42 Replenishing 42 inelastic 42 Tar Sands 41 ecologically 41 overpumping 41 headwater streams 41 minerals 41 impoverishes 41 abiotic 41 depletion 41 byproduct 41 Rainwater harvesting 41 groundwater 41 ecosphere 41 hydrocarbon fuels 41 toxic byproducts 41 reinjection 41 fuelwood 41 ANWR 41 aquatic habitats 41 extraction 40 primitively 40 sequestering carbon 40 negative externalities 40 patrimony 40 wildlife habitat 40 geological formations 40 ecological 40 mineral extraction 40 carbon sequestration 40 shale 40 gasified 40 vast amounts 40 birthright 40 tidal marshes 40 leaches 40 Biochar 40 externality 40 consumptive 40 polluting fossil fuels 40 Verleger 40 whale blubber 40 tailing ponds 40 EarthTalk 40 oxidizes 40 ecosystems 40 gaseous fuels 40 lignite coal 40 pristine wilderness 39 liquid hydrocarbons 39 conserves 39 feedstock 39 freshwater ecosystems 39 pollute 39 fungible 39 rapidly depleting 39 finders keepers 39 Self sufficiency 39 commodity 39 CO -2