The Global Assessment Report on Biodiversity and Ecosystem Services is a report by the United Nations’ Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, on the global state of biodiversity. The report states that, due to human impact on the environment in the past half-century, the Earth’s biodiversity has suffered a catastrophic decline unprecedented in human history. An estimated 82 percent of wild mammal biomass has been lost, while 40 percent of amphibians, almost a third of reef-building corals, more than a third of marine mammals, and 10 percent of all insects are threatened with extinction.
The Report examined the rate of decline in biodiversity and found that the adverse effects of human activities on the world’s species is “unprecedented in human history”: one million species, including 40 percent of amphibians, almost a third of reef-building corals, more than a third of marine mammals, and 10 percent of all insects are threatened with extinction.
Since the 16th century, at least 680 species of vertebrates have become extinct. By 2016, among mammals, more than nine percent of livestock breeds were extinct, and another 1,000 breeds are threatened with extinction. The authors have coined the expression “dead species walking” for the more than 500,000 species that are not yet extinct but, due to changes in, or reduction of, their habitats, have no chance of long-term survival.
A 2002 satellite image showing deforestation due to palm oil farming in Malaysian Borneo.
According to the Report, the threat to species diversity is human-caused. The main cause is the human land requirement, which deprives other species of their habitats. In the past 50 years, the world’s human population has doubled and biodiversity has suffered a catastrophic decline. Most notably, tropical forests have been cleared for cattle pastures in South America and for oil-palm plantations in Southeast Asia. Some 32 million hectares (79 million acres) of tropical rainforest were destroyed between 2010 and 2015, compared to the 100 million hectares (250 million acres) lost in the latter two decades of the 20th century. Already 85 percent of the world’s wetlands have been lost.
The total biomass of wild mammals has decreased by 82 percent, while humans and their farm animals now make up 96 percent of all mammalian biomass on Earth. Additionally, since 1992 the land requirement for human settlements has more than doubled worldwide; and humanity has rendered 23 percent of Earth’s land ecologically degraded and no longer usable. Industrial farming is considered to be one of the major contributors to this decline. Around 25% of the planet’s ice-free land is being used to rear cattle for human consumption.
In the oceans, overfishing is a major cause of species loss. Some 300–400 million metric tons (660–880 billion lb) of heavy metals, solvents, toxic sludge, and other wastes per year enter the water cycle from industrial facilities. Since the 19th century, the world’s coral reefs have been reduced by half.
Socioeconomic consequences include threatened loss of food production, due to loss of pollinator insects, valued at between $235 and $577 billion a year; and anticipated loss of the livelihoods of up to 300 million people, due to loss of coastal areas such as mangrove forests.
Read the summary for policy makers at https://ipbes.net/global-assessment
Source: Science and Policy for People and Nature (IPBES), 2019