Air pollution 1 Biological resources 1 Energy, Fundamentals Environmental crisis 1 Environmental ecnomics 1 Environmental ethics 1 Ethics, environmental 1 Feeding the world 1 Fossil fuelss 1 Global warming 1 Hydro electric power 1 Mineral resources 1 Nuclear energy 1 Ozone layer 1 Pesticides 1 Physical environment 1 Resource management 1 Toxicology 1 Water pollution 1 Water resources 1 biosphere 1 demography 1 pollution control 1