- The researchers examined 2.38 million records of 39,123 terrestrial species collected at 18,659 sites around the world to model the impacts on biodiversity of land use and other pressures from human activities that cause habitat loss.
- They then estimated down to about the one-square-kilometer level the extent to which those pressures have caused changes in local biodiversity, as well as the spatial patterns of those changes.
- They found that, across nearly 60 percent of Earth’s land surface, biodiversity has declined beyond “safe” levels as defined by the planetary boundaries concept, which seeks to quantify the environmental limits within which human society can be considered sustainable.
An international team of researchers has concluded that biodiversity loss has become so severe and widespread that it could affect Earth’s ability to sustain human life.
The researchers examined 2.38 million records of 39,123 terrestrial species collected at 18,659 sites around the world to model the impacts on biodiversity of land use and other pressures from human activities that cause habitat loss. They then estimated down to about the one-square-kilometer level the extent to which those pressures have caused changes in local biodiversity, as well as the spatial patterns of those changes.
They found that, across nearly 60 percent of Earth’s land surface, biodiversity has declined beyond “safe” levels as defined by the planetary boundaries concept, which seeks to quantify the environmental limits within which human society can be considered sustainable.
“We estimate that land use and related pressures have already reduced local biodiversity intactness — the average proportion of natural biodiversity remaining in local ecosystems — beyond its recently proposed planetary boundary across 58.1% of the world’s land surface, where 71.4% of the human population live,” the researchers write in an article published this month in the journal Science.
In other words, more than 70 percent of the global population lives in areas where the level of biodiversity loss has been so substantial that the ability of ecosystems to support humanity is now in question.
Biodiversity intactness has already sunk below the safe planetary boundary in most biomes, but grasslands, savannas, and shrublands were found to have been hit the hardest, with biodiversity hotspots such as forests and woodlands following close behind.
Levels of biodiversity loss are so high, the researchers said, that they could even undermine plans to continue developing the world’s economies without destroying precious natural resources. “Such widespread transgression of safe limits suggests that biodiversity loss, if unchecked, will undermine efforts toward long-term sustainable development,” the authors of the Science article added.
“It’s worrying that land use has already pushed biodiversity below the level proposed as a safe limit,” Andy Purvis, a professor in the Department of Life Sciences at Imperial College London and a co-author of the study, said in a statement.
“Decision-makers worry a lot about economic recessions, but an ecological recession could have even worse consequences — and the biodiversity damage we’ve had means we’re at risk of that happening. Until and unless we can bring biodiversity back up, we’re playing ecological roulette.”
Purvis and team said that it is possible proactive conservation could prevent future losses. They’ve made the maps from their paper and all of the underlying data publicly available in the hope that their results will be used to inform conservation policy at the national and international level.
“The greatest changes have happened in those places where most people live, which might affect physical and psychological wellbeing,” Dr. Tim Newbold of the University College London, the lead author of the study, said in a statement. “To address this, we would have to preserve the remaining areas of natural vegetation and restore human-used lands.”
CITATION
- Newbold, T., Hudson, L. N., Arnell, A. P., Contu, S., De Palma, A., Ferrier, S., … & Burton, V. J. (2016). Has land use pushed terrestrial biodiversity beyond the planetary boundary? A global assessment. Science, 353(6296), 288-291. doi:10.1126/science.aaf2201
- Steffen, W., Richardson, K., Rockström, J., Cornell, S. E., Fetzer, I., Bennett, E. M., … & Folke, C. (2015). Planetary boundaries: Guiding human development on a changing planet. Science, 347(6223). doi:10.1126/science.1259855