WASHINGTON — Humans are transforming Earth’s natural landscapes so dramatically that as many as one million plant and animal species are now at risk of extinction, posing a dire threat to ecosystems that people all over the world depend on for their survival, a sweeping new United Nations assessment has concluded.
The 1,500-page report, compiled by hundreds of international experts and based on thousands of scientific studies, is the most exhaustive look yet at the decline in biodiversity across the globe and the dangers that creates for human civilization. A summary of its findings, which was approved by representatives from the United States and 131 other countries, was released Monday in Paris. The full report is set to be published this year.
Its conclusions are stark. In most major land habitats, from the savannas of Africa to the rain forests of South America, the average abundance of native plant and animal life has fallen by 20 percent or more, mainly over the past century. With the human population passing 7 billion, activities like farming, logging, poaching, fishing and mining are altering the natural world at a rate “unprecedented in human history.”
At the same time, a new threat has emerged: Global warming has become a major driver of wildlife decline, the assessment found, by shifting or shrinking the local climates that many mammals, birds, insects, fish and plants evolved to survive in.
As a result, biodiversity loss is projected to accelerate through 2050, particularly in the tropics, unless countries drastically step up their conservation efforts.
The report is not the first to paint a grim portrait of Earth’s ecosystems. But it goes further by detailing how closely human well-being is intertwined with the fate of other species.
“For a long time, people just thought of biodiversity as saving nature for its own sake,” said Robert Watson, chair of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services,which conducted the assessment at the request of national governments. “But this report makes clear the links between biodiversity and nature and things like food security and clean water in both rich and poor countries.“