CO2, CO 2, global warming, climate change, greenhouse effect, greenhouse effect gases, emisiones de gases de efecto invernadero, carbon dioxide
Environmental aspects, etc.), Sewage, Recycling, Recycling (Waste, Organic wastes
Clima, Cambios, desarrollo sostenible
POPULATION, Environmental aspects, Economic aspects, Sustainable development, Overpopulation, Population forecasting, Malthusianism, Population policy