Roughly half of Earth’s ice-free land remains without significant human influence, according to a new study.
The study in Global Change Biology compares four recent global maps of the conversion of natural lands to human land uses to reach its conclusions. The more affected half of Earth’s lands includes cities, croplands, and places intensively ranched or mined.
“The encouraging takeaway from this study is that if 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,” says lead author Jason Riggio, a postdoctoral scholar at the Museum of Wildlife and Fish Biology at the University of California, Davis.
The study aims to inform the upcoming global Convention on Biological Diversity—the Conference of Parties 15. The historic meeting was scheduled to occur in China this fall but was postponed due to the coronavirus pandemic. Among the meeting’s goals is to establish specific, and higher, targets for land and water protection.
“Human risk to diseases like COVID-19 could be reduced by halting the trade and sale of wildlife, and minimizing human intrusion into wild areas.”
Approximately 15% of the Earth’s land surface and 10% of the oceans are currently protected in some form. However, led by organizations including Nature Needs Half and the Half-Earth Project, there have been bold global calls for governments to commit to protecting 30% of the land and water by 2030 and 50% by 2050.
Intact natural lands across the globe can help purify air and water, recycle nutrients, enhance soil fertility and retention, pollinate plants, and break down waste products. The value of maintaining these vital ecosystem services to the human economy has been placed in the trillions of US dollars annually.
Land conservation and diseases like COVID-19
The coronavirus pandemic now shaking the globe illustrates the importance of maintaining natural lands to separate animal and human activity. The leading scientific evidence points to the likelihood that SARS-CoV2, the virus that causes the disease COVID-19, is a zoonotic virus that jumped from animals to humans. Ebola, bird flu, and SARS are other diseases known to have spilled over into the human population from nonhuman animals.
“Human risk to diseases like COVID-19 could be reduced by halting the trade and sale of wildlife, and minimizing human intrusion into wild areas,” says senior author Andrew Jacobson, professor of GIS and conservation at Catawba College in North Carolina.
“…these targets are still within reach.”
Jacobson says that regional and national land-use planning that identify and appropriately zone locations best suited to urban growth and agriculture could help control the spread of human development. Establishing protections for other landscapes, particularly those currently experiencing low human impacts, would also be beneficial.
Which areas have the least human impact?
Among the largest low-impact areas are broad stretches of boreal forests and tundra across northern Asia and North America and vast deserts like the Sahara in Africa and the Australian Outback. These areas tend to be colder and/or drier and less fit for agriculture.
“Though human land uses are increasingly threatening Earth’s remaining natural habitats, especially in warmer and more hospitable areas, nearly half of Earth still remains in areas without large-scale intensive use,” says coauthor Erle Ellis, professor of geography at the University of Maryland-Baltimore County.
Areas having low human influence do not necessarily exclude people, livestock, or sustainable management of resources. A balanced conservation response that addresses land sovereignty and weighs agriculture, settlement, or other resource needs with the protection of ecosystem services and biodiversity is essential, the authors note.
“Achieving this balance will be necessary if we hope to meet ambitious conservation targets,” says Riggio. “But our study optimistically shows that these targets are still within reach.”
Source: UC Davis