Global human influence maps reveal clear opportunities in conserving Earth’s remaining intact terrestrial ecosystems

Leading up to the 2020 Convention on Biological Diversity there is
momentum around setting bold conservation targets. Yet it remains unclear
how much of Earth’s land area remains without significant human influence
and where this land is located. We compare four recent global maps of
human influences across Earth’s land, Anthromes, Global Human
Modification, Human Footprint, and Low Impact Areas, to answer these
questions. Despite using various methodologies and data, these different
spatial assessments independently estimate similar percentages of the
Earth’s terrestrial surface as having very low (20-34%) and low (48-56%)
human influence. Three out of four spatial assessments agree on 46% of the
non-permanent ice- or snow-covered land as having low human influence.
However, much of the very low and low influence portions of the planet are
comprised of cold (e.g., boreal forests, montane grasslands and tundra) or
arid (e.g., deserts) landscapes. Only four biomes (boreal forests,
deserts, temperate coniferous forests and tundra) have a majority of
datasets agreeing that at least half of their area has very low human
influence. More concerning, <1% of temperate grasslands, tropical
coniferous forests and tropical dry forests have very low human influence
across most datasets, and tropical grasslands, mangroves and montane
grasslands also have <1% land identified as very low influence
across all datasets. These findings suggest that about half of Earth’s
terrestrial surface has relatively low human influence and offers
opportunities for proactive conservation actions to retain the last intact
ecosystems on the planet. However, though the relative abundance of
ecosystem areas with low human influence varies widely by biome,
conserving these last intact areas should be a high priority before they
are completely lost.