Conservation of the environment Environmental science, engineering & technology 18 Environmental policy & protocols 12 Applied ecology 11 Ecological science, the Biosphere 11 Environmental management 11 Environmental economics 9 Social impact of environmental issues 7 Conservation of wildlife & habitats 6 Civil engineering, surveying & building 5 Climate change 5 Environment law 5 Environmentalist thought & ideology 5 Political economy 5 Regional geography 5 The Earth: natural history general 5 The environment 5 Biodiversity 4 Slovenia 4 Sustainability 4 Biology, life sciences 3 Christianity 3 Earth sciences 3 Natural history 3 Religion: general 3 Sustainable agriculture 3 Agriculture & farming 2 Business studies: general 2 Economic systems & structures 2 Forestry & silviculture: practice & techniques 2