Natural history 16 The Earth: natural history general 13 Applied ecology 11 Environmental policy & protocols 8 Conservation of the environment 7 Environmental management 7 Biology, life sciences 6 Environmental science, engineering & technology 6 Climate change 4 Earth sciences 3 Development economics & emerging economies 2 Ecological science, the Biosphere 2 Environmental economics 2 Gender studies, gender groups 2 History of science 2 Mining industry 2 Physiology 2 Research & information: general 2 Science: general issues 2 Agriculture & related industries 1 Ancient religions & mythologies 1 Animals & society 1 Asian history 1 Australasian & Pacific history 1 Biodiversity 1 Biography: general 1 Biography: historical, political & military 1 British & Irish history 1 Business & management 1 Central government 1