Environmental aspects Population Sustainable development 15 Economic aspects 13 Economic development 9 Overpopulation 8 Human ecology 6 more ... Management 6 Natural resources 6 Biodiversity 5 Birth control 5 Climatic changes 5 Population forecasting 5 Population policy 5 Social aspects 5 Cities and towns 4 Emigration and immigration 4 Moral and ethical aspects 4 Public health 4 Social conditions 4 Conservation of natural resources 3 Ecology 3 Economic conditions 3 Effect of human beings on 3 Forecasting 3 Growth 3 Pollution 3 Population density 3 Quality of life 3 Religious aspects 3 less ...