Vertebrate wildlife populations across the globe have dropped dramatically over the past 50 years, according to a new World Wildlife Fund (WWF) report, published last week. Between 1970 and 2018, populations declined an average of 69 percent, the researchers say.
“It is very much a red flag and a warning signal that… the life support system on Earth is in trouble,” Rebecca Shaw, chief scientist for the World Wildlife Fund, tells NPR’s Leila Fadel. “It is a very sharp decline.”
Every two years, the WWF releases its Living Planet Report based on the Zoological Society of London’s Living Planet Index (LPI). This index measures the “state of the world's biological diversity based on population trends of vertebrate species from terrestrial, freshwater and marine habitats,” per its website. This year’s edition looked at more than 5,000 species and nearly 32,000 animal populations.
The LPI uses lots of survey data to examine each population individually and calculate its change over time. These changes are then averaged together to estimate the average decline in monitored populations across the world. In 2020, scientists calculated a global average decline of 68 percent, and four years ago, the number was 60 percent.
In the past, this figure has often been misunderstood, Vox’s Benji Jones reports. It’s “constantly being interpreted as we’ve lost 69 percent or 68 percent of the abundance of animals worldwide,” Brian Leung, an ecologist at McGill University in Canada, tells the publication. “It’s not that.” It measures the rate of a species’ decline, not the number of individuals lost.
The 2022 report found that some species and regions were hit harder than others. Freshwater species dropped across the globe by an average of 83 percent. Vertebrate populations in Latin America and the Caribbean fell an average of 94 percent.
“The worst declines are in the Latin America region, home to the world’s largest rainforest, the Amazon,” Tanya Steele, chief executive at WWF-UK, tells the Guardian’s Patrick Greenfield. “Deforestation rates there are accelerating, stripping this unique ecosystem not just of trees but of the wildlife that depends on them and of the Amazon’s ability to act as one of our greatest allies in the fight against climate change.”
The report points to overexploitation, invasive species, pollution, climate change, habitat loss and diseases as main drivers of the decline. But it also offers some hope: The LPI indicates that half of the monitored populations actually show an increasing trend, per Vox.
“Normally, when people think of endangered wildlife, it’s all the iconic animals such as elephants, tigers and pandas,” Marco Lambertini, director general of WWF International, tells CNN’s Hafsa Khalil. “Funnily enough, some of these animals have started to bounce back. Tigers are almost double their number and pandas have gone up about 20 percent.”
Still, many populations have fared poorly: The eastern lowland gorilla, for one, saw an estimated 80 percent decline in the Democratic Republic of the Congo’s Kahuzi-Biega National Park between 1994 and 2019, per a WWF statement.
In the report, the authors call for “system-wide changes in how we produce and consume, the technology we use and our economic and financial systems” to help create a future where people and nature can thrive.
“These plunges in wildlife populations can have dire consequences for our health and economies,” Shaw says in the statement. “When wildlife populations decline to this degree, it means dramatic changes are impacting their habitats and the food and water they rely on. We should care deeply about the unraveling of natural systems because these same resources sustain human life.”