Environmental protection Environmental policy 49 Pollution 31 Environmental law 28 Environmental sciences 22 Ecology 21 Environmental management 18 Ecofeminism 16 Climatic changes 12 Human ecology 12 Sustainability 11 Sustainable development 11 Environmental degradation 10 Global warming 10 Conservation of natural resources 9 Environmental problem 8 Global environmental change 8 Nature conservation 8 Environmental aspects 7 Environmental engineering 7 Environmental problems 7 Environmental economics 6 Natural Resource Economics, (New March 2000) 6 Natural resources 6 Greenhouse gas mitigation 5 Policy and Planning 5 Environmental health 4 Environmental impact 4 Environmental responsibility 4 Environmentalism 4