Human ecology History 536 Nature 465 Effect of human beings on 406 Environmental conditions 268 Religious aspects 235 Social aspects 215 more ... Philosophy 213 Environmental policy 179 Environmental aspects 164 Environmental protection 158 Ecology 149 Human beings 136 Christianity 117 Climatic changes 114 Environmental ethics 105 Social conditions 102 Sustainable development 102 Effect of environment on 101 Environmentalism 99 Environmental degradation 94 Philosophy of nature 94 Conservation of natural resources 75 Environmental sciences 73 Human geography 73 Natural history 71 Social ecology 67 Antiquities 66 Economic aspects 62 Social life and customs 60 less ...