The ArchaeoGlobe Project assessed knowledge on human land use over the past 10,000 years, through the contributions of more than 200 archaeologists. It concluded that, by 3,000 years ago, most of Earth was already transformed by hunter-gatherers, farmers and pastoralists. Examples of how human societies are changing the planet abound - from building roads and houses, clearing forests for agriculture and digging train tunnels, to shrinking the ozone layer, driving species extinct, changing the climate and acidifying the oceans. Human impacts are everywhere.