Just 5% of the world’s land is untouched by human activity, highlighting the importance of conserving areas other than pristine wilderness, a study suggests.
Researchers from The Nature Conservancy assessed the extent to which land had been modified by humans through 13 different activities from settlements and agriculture to roads, railways, mining and energy developments such as oil wells and wind farms.
Their study found that 95% of the world’s land area, excluding Antarctica, had been modified by people – and the vast majority of landscapes (84%) are facing multiple pressures.
The study, published in the journal Global Change Biology, suggests the degree to which land has been affected by human activity is higher than previously reported.
Only 30% of regional ecosystems or habitats – which range from mangroves, savanna and deserts to broadleaf and conifer forests – have seen low levels of human impact and retain most of their natural land, which is distant from settlements, agriculture and other pressures.
Just over half (52%) have been moderately changed or affected by humans, the research found.
In many of these landscapes, only up to half of the land is formed of natural habitat, intermixed with towns, farming, transport links and other uses.
And they are on a threshold where further loss or fragmentation of habitat could cause “precipitous declines” in wildlife and natural services that humans rely on to survive, such as provision of fresh water and crop pollination.
These moderately modified regions are in many ways a more pressing conservation priority than either intact wilderness or areas where humans have had a high impact, the researchers argue.
Christina Kennedy, lead author and senior scientist at The Nature Conservancy (TNC), said they needed proactive development, landscape protection and restoration strategies to maintain critical habitats to support nature and natural services.
But she warned these kind of areas were not commonly recognised under current conservation schemes, and were “likely to fall through the cracks”.
She said: “Our study reinforces that most of the world’s landscapes are complex mosaics of natural lands interspersed among human land uses.
“In light of this reality, conservation actions must include both protection and restoration strategies in the right places and in the right amounts to ensure functioning ecosystems, an approach taken by TNC in many of the landscapes where we work.”
Joe Kiesecker, lead scientist at TNC, added: “Conservation organisations agree that the large intact landscapes remaining on the planet are conservation priorities.
“But our results suggest that less of the world’s land remains unaltered by human activities, and most are in a state of intermediate modification at the threshold of critical tipping points.
“These areas also need recognition and the attention necessary to conserve the values they provide for people and nature.”