Half of the planet’s land areas can still be saved from us

Over the past century Earth has undergone dramatic changes for the worse. The number of people, which in 1900 stood at under 2 billion, doubled and then doubled again to nearly 8 billion today. In tandem, more and more once pristine land has been converted to manmade uses: agriculture, infrastructure, housing.

Wildlife habitats have been decimated. Forests have been felled. Coastal areas have been redeveloped. Yet not all is lost. Not yet at any rate.

An international team of researchers from the National Geographic Society and the University of California has mapped Earth for our collective footprint on ice-free land areas to see how much of it has escaped being put to anthropogenic uses.

They estimate that around half of terrestrial areas on the planet (somewhere between 48% and 56%) have been relatively unimpacted by us. Three out of four spatial assessments conducted by the scientists have yielded the result that nearly half of the non‐permanent ice‐ or snow‐covered land has had low human influence, especially in areas with frigid climates such as large parts of Canada and Siberia in Russia.

That sounds like good news, but they caution in their newly published study that “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.”

The worst-affected have been temperate grasslands, tropical coniferous forests and tropical dry forests, only a mere 1% of which have been left largely unaffected by humans. Tropical grasslands and mangrove forests have fared just as badly. This is especially disconcerting as these areas have been among the most biodiverse on the planet.

Overall, half of Earth’s terrestrial surface has had relatively low human influence, which “offers opportunities for proactive conservation actions to retain the last intact ecosystems on the planet” the experts write. However, they add, “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.”

At present around 15% of the planet’s land surface area is protected in some form, as are around 10% of its oceans. Conservationists have called for doubling the size of protected land areas by 2030. They would also like to see half of the oceans protected by the middle of the century to ensure the planet’s remaining ecosystems could still thrive.

“[I]f we act quickly and decisively, there is a slim window in which we can still conserve roughly half of Earth’s land in a relatively intact state,” stresses the study’s lead author Jason Riggio, a scholar at the UC Davis Museum of Wildlife and Fish Biology.