Wildlife populations have fallen by alarming 68% average in 46 years due to rampant human activity: WWF report
In the last 50 years, the world has been transformed by an explosion in global trade, consumption and human population growth, as well as an enormous move towards urbanization. These underlying trends are driving the destruction and degradation of nature, with the world now overusing natural resources at an unprecedented rate.
Scientists now warn that global populations of mammals, birds, amphibians, reptiles and fish have suffered an average two-thirds decline in less than half a century. The "catastrophic decline" is due, in large part, to the very same environmental destruction – such as deforestation, unsustainable agriculture and illegal wildlife trade – which is contributing to the emergence of zoonotic diseases like Covid-19, they explain.
The World Wildlife Fund (WWF) Living Planet Report 2020 sounds the alarm for global biodiversity, showing an alarming average fall of 68% in animal population sizes tracked over 46 years (1970-2016). It presents a comprehensive overview of the state of the natural world through the Living Planet Index (LPI), which tracks the abundance of 20,811 populations of 4,392 vertebrate species globally.
Researchers found that the main cause of the dramatic decline in species populations on land is habitat loss and degradation, including deforestation, driven by how humans produce food. According to experts, 75% of the Earth's ice-free land surface has already been significantly altered, most of the oceans are polluted, and over 85% of the area of wetlands has been lost.
This destruction of ecosystems has led to 1 million species (500,000 animals and plants and 500,000 insects) being threatened with extinction over the coming decades to centuries.
"The LPI provided by the Zoological Society of London (ZSL) shows that factors believed to increase the planet's vulnerability to pandemics were also some of the drivers behind the 68% average decline in global vertebrate species populations between 1970 and 2016," says the report.
Biodiversity declining at different rates in different places
The 94% decline in the LPI for tropical subregions of the Americas is the most striking result observed in any region. The conversion of grasslands, savannahs, forests and wetlands, the overexploitation of species, climate change and the introduction of alien species are key drivers, reveals the analysis.
Endangered species include the eastern lowland gorilla, whose numbers in the Kahuzi-Biega National Park, Democratic Republic of Congo, have seen an estimated 87% decline between 1994 and 2015, mostly due to illegal hunting. The number of African grey parrots in southwest Ghana fell by up to 99% between 1992 and 2014 due to threats posed by trapping for the wild bird trade and habitat loss.
Freshwater biodiversity is declining far faster than that in oceans or forests. The report says that wildlife populations found in freshwater habitats have suffered a drop of 84%, the starkest average population decline in any biome, equivalent to 4% per year since 1970. Most of the declines are seen in freshwater amphibians, reptiles and fish and are recorded across all regions, particularly Latin America and the Caribbean.
One example is the spawning population of the Chinese sturgeon in China’s Yangtze River, which declined by 97% between 1982 and 2015 due to the damming of the waterway. The impacts of this decline directly affect food security and livelihoods.
"The Living Planet Report 2020 underlines how humanity's increasing destruction of nature is having catastrophic impacts not only on wildlife populations but also on human health and all aspects of our lives. We can’t ignore the evidence – these serious declines in wildlife species populations are an indicator that nature is unraveling and that our planet is flashing red warning signs of systems failure. From the fish in our oceans and rivers to bees, which play a crucial role in our agricultural production, the decline of wildlife affects directly nutrition, food security and the livelihoods of billions of people," cautions Marco Lambertini, WWF International Director-General.
Reversing the trend
The report calls for urgent measures to reverse this trend by 2030 to avoid irreversible biodiversity loss. It includes modeling, which shows that without further efforts to counteract habitat loss and degradation, global biodiversity will continue to decline. Based on a paper, co-authored by WWF and over 40 NGOs and academic institutions and published in Nature, the modeling suggests that stabilizing and reversing the loss of nature caused by humans’ destruction of natural habitats will only be possible if bolder, more ambitious conservation efforts are embraced and transformational changes made to the way people produce and consume food.
Changes suggested include making food production and trade more efficient and ecologically sustainable, reducing waste and favoring healthier and more environmentally-friendly diets. Implementing these measures together rather than in isolation will allow the world to more rapidly alleviate pressures on wildlife habitats, thereby reversing biodiversity trends from habitat loss decades earlier than strategies that allow habitat losses and then attempt to reverse them later on, researchers recommend.
The modeling indicates that if the world carries on with "business as usual", rates of biodiversity loss seen since 1970 will continue over the coming years and wildlife will be driven to extinction, which would threaten the ecosystems that humans depend on for survival. "These losses would at best take decades to reverse, and further irreversible biodiversity losses are likely, putting at risk the myriad ecosystem services that people depend on," explains David Leclère, lead author of the paper and research scholar at the International Institute of Applied System Analysis.