Nature Effect of human beings on 672 Human ecology 319 History 240 Religious aspects 170 Ecology 122 Environmental conditions 118 more ... Environmental aspects 90 Social aspects 78 Philosophy 67 Christianity 61 Environmentalism 61 Natural history 61 Environmental degradation 56 Environmental policy 56 Environmental protection 54 Climatic changes 52 Global environmental change 50 Human beings 49 Effect of environment on 46 Nature conservation 41 Philosophy of nature 39 Psychological aspects 35 Political aspects 33 Landscape changes 32 Environmental ethics 31 Pollution 31 human ecology 28 Human-animal relationships 27 Moral and ethical aspects 27 less ...