Human ecology 1,320 History 267 Nature 253 Religious aspects 252 Effect of human beings on 175 Ecology 141 Christianity 131 Philosophy 124 Social aspects 117 SOCIAL SCIENCE 112 Environmental conditions 105 General 102 Human beings 102 human ecology 98 Environmental aspects 85 Environmental policy 81 Environmental protection 76 Indigenous peoples 76 Climatic changes 73 Environmentalism 67 Environmental ethics 66 Social conditions 66 Anthropology 57 NATURE 56 Antiquities 54 Social ecology 53 Philosophy of nature 50 SCIENCE 49 Environmental degradation 47 Human ecology in literature 47