Three centuries ago, humans were intensely using just around 5 percent of the Earth’s land. Now, it’s almost half.

Environmental scientist Erle Ellis has studied the impact of humanity on the Earth for decades, with a recent focus on categorizing and mapping how humans use the land—not just now, but in the past. And his team’s results show some startling changes. Three centuries ago, humans were intensely using just around 5 percent of the planet, with nearly half the world’s land effectively wild. Today, more than half of Earth’s land is occupied by agriculture or human settlements.

“Climate change is only recently becoming relevant,” said Ellis, a professor at the University of Maryland, Baltimore County. “If it keeps going how it is, it will become the dominant shaper of ecology in the terrestrial realm, but right now the dominant shaper of ecology is land use.”

In contrast to the typical division of the world into ecological “biomes,” Ellis and his team at the Laboratory for Anthropogenic Landscape Ecology map what they call “anthromes,” or “anthropogenic biomes.” These show the intersection of ecology and human land use.

....