A new paper by Israeli researchers has not only confirmed a disputed estimate that wildlife populations have declined by over two-thirds in the past 50 years, but showed that the true drop may have been even more severe, according to a Monday statement.
The study, published last week in the journal Nature, should spur people to action and reconsider the relationship between human beings and nature, said the authors, from Ben Gurion University of the Negev and Tel Aviv University.
“Rather than discourage us from action, we feel that our work should be viewed as a call to arms,” said co-author Shai Meiri from Tel Aviv University. “Rapid and comprehensive changes in how we view our relationships with nature are needed – and the onus is on us to make sure they happen before it is too late.”
Researchers had re-examined findings of 2020 Living Planet Report, compiled biannually for the past 24 years by the World Wildlife Fund and the Zoological Society of London, which estimated there was an average 68 percent drop in vertebrate populations around the world between 1970 and 2016.
Some scientists had challenged the figure, saying it was skewed by a few populations that had experienced a massive decline and were “tipping the scales for all 20,811 of the populations monitored in the Living Planet Report,” the statement said.
Gopal Murali, lead author of the paper, said criticism of the report “was unfair” because its detractors had adjusted the estimate by removing less than 3% of the most declining populations, arriving a new figure that showed no net loss trend.
“However, by removing only those populations experiencing greatest declines – these researchers, in essence, gave much more weight to those populations showing greatest increases,” he explained.
The Israeli researchers rebalanced the estimate by also removing the most increasing populations, arriving at a 65% decline over the past five decades.
Going further, the researchers took a closer look at the overlap between monitored populations and protected wildlife areas around the world. The data was then compared to random samples from other locations and their proximity to the global network of protected areas. The results showed that populations that were sampled for the Living Planet Report were “much more likely to be inside protected areas than would be expected to occur by chance.”
It indicated that the true wildlife decline could be even direr than previously thought.
“This is truly alarming,” said co-author Gabriel Caetano. “If populations inside protected areas – where we focus a lot of our conservation efforts – are doing so badly, those that reside outside protected areas are probably worse off. The true situation of nature – mostly not monitored or protected – may be much worse.”
“A lot of focus and attention by the public, governments, and NGOs is focused on the extinction of species,” the statement said. “Nevertheless, extinction is but the unwanted conclusion of a process that starts with harm to individual animals or plants by people and leads to their populations declining.”
Authors called for greater monitoring of populations and species in different locations and warned that “many populations, species, and pristine locations would be lost forever without concentrated and direct action,” the statement said.