Environmental economics Sustainable development 30 Research & information: general 28 Environmental policy 24 Economic aspects 18 Environmental Economics 9 climate change 9 Climatic changes 6 Conservation of the environment 6 Environmental aspects 6 Development economics 5 Economic History 5 Economic development 5 Economics 5 Environmental protection 5 Finance 5 Natural resources 5 groundwater 5 China 4 Economic growth 4 Economic policy 4 Environment 4 Government policy 4 Management 4 Political economy 4 Research 4 biodiversity 4 drought 4 metals 4 water quality 4