Agricultural revolution Alternative energy resources Biomes Climate warming Conventional energy systems Earth systems and ecology Ecology-- Biodiversity-- Conservation Economic expansion Food supply Human impact on the environment Human population, growing Industrial revolution Land biomes Land resources Nuclear energy Ozone depletion People Environments Prehistoric human societies in the stone age Radioactive wastes Resources and energy Sustainable energy systems Sustainable society Water biomes Wild species, decline Wildlife resources Wildlife species, preserving human civilizations stone age human societies sustainable communities