Natural history Applied ecology 9 Environmental policy & protocols 8 Environmental science, engineering & technology 5 Environmental management 4 Biology, life sciences 3 Climate change 3 Conservation of the environment 3 The Earth: natural history general 3 Development economics & emerging economies 2 Ecological science, the Biosphere 2 Gender studies, gender groups 2 History of science 2 Mining industry 2 Physiology 2 Science: general issues 2 Agriculture & related industries 1 Asian history 1 Biodiversity 1 Business & management 1 Central government 1 Central government policies 1 Earth sciences 1 Environment law 1 Environmental economics 1 General & world history 1 Geography 1 History of Western philosophy 1 History of the Americas 1 International relations 1