A report released Thursday by the nonprofit conservation group World Wildlife Fund (WWF) said the world's wildlife populations have plunged by an average of 68% in just four decades, with human consumption behind the decline.
The 2020 Living Planet Report, a collaborative effort involving about 125 individuals, tracked almost 21,000 populations from 1970 to 2016, including species of mammals, birds, fish, reptiles and amphibians.
Experts say that deforestation for the purpose of farming and wildlife trade were the main factors of the drop. However, the introduction of nonnative species and changing habitats of grasslands, savannas, forests and wetlands as a result of climate change were key components as well.
"Deforestation, and in the larger sense habitat loss — which is driven by how we produce and consume food — is the main cause of this dramatic decline," said Fran Price, leader of the global forest practice at WWF International.
However, wildlife populations are not the only ones who are in danger as a result of species decline and deforestation. Scientists say that the rapid destruction of the environment plays a dramatic role in the spread of zoonotic diseases, which are passed from animals to humans, such as COVID-19.
Forests act as buffers to keep zoonotic diseases away from humans, environmentalists say, and the more that are destroyed, the greater the risk of exposure for people.
"The longer the wildlife stay in supply chains with other humans and people, the greater the risk of spillover of a wildlife disease to humans,” said Rebecca Shaw, chief scientist at WWF. “We are playing Russian roulette with the threat of pandemics, and in the end, we will lose ... big. And COVID-19 is only the beginning."
The authors of the report say that regions of Latin American and the Caribbean faced the biggest impacts, with an average decline of 94% in wildlife populations in the area. Price believes large-scale commercial production of palm oil, soy and beef in the area has contributed substantially to the drop.
Environmentalists say conserving existing forests and restoring damaged ones reduces the risk of flooding, helps limit global warming by storing more carbon, and protects biodiversity. As of 2019, data from Global Forest Watch, a real-time monitor of forests worldwide, indicates that tropical rainforests are disappearing at a rate of 12 million hectares a year as a result of deforestation.
Experts say that while climate change is not yet the biggest cause of biodiversity loss, in the coming years, climate change will become a key driver of species decline.
In their report, WWF members called for stronger commitments by governments and corporations around the world to make global supply chains more sustainable. Experts say that consumers, too, must understand the impacts of their purchasing habits on nature.
Researchers at the University of Oxford said Thursday that climate change solutions must go beyond tree planting and greenhouse gas removal. They recommended nature-based interventions, such as restoring forests and mangroves. These have been shown to alleviate approximately 60% of climate-related pressures, such as flooding and a loss of food production, in areas around the world.