Ecological science, the Biosphere 150 Research & information: general 116 Applied ecology 105 Biology, life sciences 62 Science: general issues 62 Environmental science, engineering & technology 54 Environmental policy & protocols 50 Environmental economics 49 Environmental management 39 Conservation of the environment 37 The environment 37 Development economics & emerging economies 34 Sustainability 31 Climate change 25 Human geography 25 Technology: general issues 25 Social impact of environmental issues 24 Central government policies 23 Geography 23 Sociology 23 Anthropology 21 Social & cultural anthropology, ethnography 21 Society & social sciences 21 Biodiversity 20 City & town planning - architectural aspects 19 Environmentalist thought & ideology 19 Earth sciences, geography, environment, planning 17 Environmentally-friendly architecture & design 17 Botany & plant sciences 16 History of engineering & technology 16