Applied ecology 5 Environmental policy & protocols 5 Climate change 4 Development economics & emerging economies 4 Environmental economics 4 Environmental science, engineering & technology 4 Environment law 3 Environmental monitoring 3 Earth sciences, geography, environment, planning 2 Environmental management 2 Environmental medicine 2 Pollution control 2 Sustainability 2 Agricultural science 1 Agriculture & farming 1 Analytical chemistry 1 Biotechnology 1 Central government 1 Conservation of the environment 1 Earth sciences 1 Economics 1 Energy 1 Human geography 1 Medicine: general issues 1 Meteorology & climatology 1 Migration, immigration & emigration 1 Politics & government 1 Pollution & threats to the environment 1 Public health & preventive medicine 1 Social classes 1