ENVIRONMENT 1 million species under threat of extinction because of humans, biodiversity report finds
A sweeping report assessing the state of the natural world found that humans are having an “unprecedented” and devastating effect on global biodiversity, with about 1 million animal and plant species now threatened with extinction.
A summary of the report’s findings was released Monday by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, which was established in 2012 by the United Nations Environment Programme and includes representatives from 132 countries.
Robert Watson, the panel’s chair and a professor of environmental sciences at the University of East Anglia in the U.K., said evidence collected over the past five decades from roughly 15,000 scientific and government studies paints “an ominous picture.”
“The health of ecosystems on which we and all other species depend is deteriorating more rapidly than ever,” he said in a statement. “We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide.”
The report, which did not list individual species, found that 25 percent of mammals, more than 40 percent of amphibian species, nearly 33 percent of sharks and 25 percent of plant groups are threatened with extinction. Based on these proportions, the researchers estimated that approximately 1 million animal and plant species could die out, many “within decades.”
Since the 16th century, humans have driven at least 680 vertebrate species to extinction, including the Pinta Island tortoise. The last known animal of this subspecies, a giant tortoise nicknamed Lonesome George, died at the Galapagos National Park in Ecuador in 2012. A subspecies of the Javan rhino went extinct in 2011, and the western black rhino and northern white rhino are extinct in the wild, according to the World Wildlife Fund.
“The essential, interconnected web of life on Earth is getting smaller and increasingly frayed,” Josef Settele, the report’s co-chair, said in a statement.
Extinctions have occurred throughout the planet’s history, but the report found that human actions threaten more species now than ever before, with the global rate of species extinction over the past 50 years already “at least tens to hundreds of times higher than it has averaged over the past 10 million years.”
This quickening pace should be cause for alarm, according to David Wagner, a professor of ecology and evolutionary biology at the University of Connecticut, who was not involved with the report.
“It’s happening faster than organisms can respond evolutionarily,” Wagner said. “That means new species generation won’t be able to keep pace with the loss of species.”
This could have serious consequences for the stability of ecosystems around the world, which in turn could directly affect human health, experts say. The interactions between animals, plants, humans and the environment make up a complex web. Disruptions to any part of this biological architecture can have significant, cascading effects.
For instance, humans need food to survive. More than three-quarters of the world’s food crops rely, at least in part, on the activities of bees, wasps, butterflies and other pollinators, according to the Food and Agriculture Organization of the United Nations. The new U.N. report found that 10 percent of insect species are under threat.
“When you lose a species, think of it like a fabric, and you’re taking and plucking one of the strings,” said Brett Scheffers, a conservation ecologist at the University of Florida in Gainesville, who was not involved with the report. “Over time, the fabric gets looser and less stable. These are the types of changes we’re observing where entire ecosystems collapse.”