Environmental economics 6 Research & information: general 3 Earth sciences, geography, environment, planning 2 Environmental management 2 Environmental science, engineering & technology 2 History of engineering & technology 2 Manufacturing industries 2 Aid & relief programmes 1 Biochemical engineering 1 Climate change 1 Coins, banknotes, medals, seals (numismatics) 1 Computer modelling & simulation 1 Earth sciences 1 Ecological science, the Biosphere 1 Energy industries & utilities 1 Environmental policy & protocols 1 Hydrology & the hydrosphere 1 Limnology (freshwater) 1 Management of specific areas 1 Meteorology & climatology 1 Pharmaceutical industries 1 Physical geography & topography 1 Pollution control 1 Science: general issues 1 Waste management 1 Water supply & treatment 1