A new study shines a fresh light on the sobering reality of the biodiversity crisis. According to an analysis published in Proceedings of the National Academy of Sciences (PNAS), extractive human activity has caused the extinction of entire branches of the ‘Tree of Life’.
The ‘Tree of Life’ is a pictorial representation, first developed by Charles Darwin, of the evolutionary relationship between species.
Notably, the research warned that:
Beyond any doubt, the human-driven sixth mass extinction is more severe than previously assessed and is rapidly accelerating.
Alarming extinction rates
Multiple studies have attempted to quantify the extinction of species over specific timeframes. For example, 2019 research indicated that nearly 600 plant species have gone extinct within the last 250 years. Meanwhile, Birdlife International has suggested that 182 bird species have become extinct since 1500.
Yet while these previous studies have illustrated the rapid rate of species extinction, the new research is the first of its kind to examine the loss of entire genera.
In the classification of living beings, a ‘genus’ – genera plural – lies between the ranks of ‘species’ and ‘family’. For example, dogs are a species belonging to the genus canis, which is in the canid family. The genus canis includes the domestic dog’s closest wild relatives, such as wolves, coyotes, jackals, and dingoes.
The analysis compared the present rate of extinction of genera with the background rate, i.e the rate at which extinction took place over the long term, specifically the last million years. It found that the present rate of extinction was over 35 times higher than the background rate.
Mass extinction
According to the extinction rate for that long-term time period, the study’s researchers said they would have anticipated just two genera to have gone extinct in the last five centuries. Instead, they identified that destructive human exploitation of the natural world had sent 73 genera to extinction. The majority of these have been lost in the last 200 years.
There are some 5,400 genera, which comprise of approximately 34,600 species. The researchers relied largely on species listed as extinct by the International Union for Conservation of Nature (IUCN). They focused on vertebrate species (excluding fish), for which more data are available.
The study estimated that the extinction of 73 genera should have taken 18,000 years, not 500. However, the research did acknowledge that such estimates remain uncertain. This is because not all species are known and the fossil record also remains incomplete.
What’s more, the study suggested that if destructive human activities were to drive all currently-endangered genera to extinction by the year 2100, this would be on average 354 times higher than the background extinction rate. As such, the study suggested that the world is in the grip of the sixth mass extinction. The last such event was the asteroid that wiped out the dinosaurs 66m years ago.
The “drivers of ecological breakdown”
The researchers pointed to human activities as the primary driver of this rapid extinction rate. This included, for example, the destruction of habitats for crops or infrastructure, as well as overfishing and hunting. But the analysis stopped short of attributing specific blame.
Previous research, however, has singled out how rich, Global North nations are the principle source of rampant global biodiversity loss. For example, a 2022 study found that between 1970 and 2017, high-income countries were responsible for nearly three quarters of “global excess resource use”. As a result, the analysis concluded that these high-income nations were:
the primary drivers of global ecological breakdown
Similarly, a separate study from 2021 detailed that rich nations have been spurring deforestation in biodiverse hotspots around the world. Between 2001 and 2015, an enormous 91 to 99% of the deforestation footprints of some rich countries took place abroad. This included the footprints of the UK, Germany, France, Italy and Japan. Significantly, the study identified that between 46 to 57% of this came from ecologically-rich tropical rainforests.
Moreover, others have honed in on colonialism and how it sits at the root of ecological breakdown. In an opinion piece for the journal PLOS Global Public Health, a group of Indigenous researchers argued that:
climate change and biodiversity loss are directly caused by colonialism and the perpetuation of colonial practices, strategies, policies, and judicial systems.
In other words, the extractive and exploitative tools of colonialism directly led to the decimation of biodiversity.
Loss and damage for biodiversity loss
Of course, the timeframe in which the new study found heightened genus losses does also coincide with colonial and capitalist global expansion and industrialisation. While this study did not explicitly make this connection, it did highlight that:
extinction rates will likely greatly accelerate in the next few decades due to drivers accompanying the growth and consumption of the human enterprise such as habitat destruction, illegal trade, and climate disruption
Given that these impacts are largely driven by rich corporations in the Global North, the new research lends weight to demands for these countries to pay up for continued ecological harm.
For instance, a May 2023 opinion piece in the journal Nature called for rich countries to pay “loss and damage finance” to the Global South for biodiversity loss. The scientists argued that:
biodiversity loss — driven primarily by consumption in the Global North — can and does result in economic and non-economic losses for people in the Global South.
As the Canary has previously reported, Global South countries have been calling for an equivalent fund towards the impacts of the climate crisis.
Co-author of the new study Gerardo Ceballos warned that the research showed that the window of opportunity for the world to act is “rapidly closing.” He suggested that the priority should be to halt the destruction of natural habitats and to restore those that have been lost. Crucially, he said:
there is still time to save many genera. There are 5,400 genera, we can save many of them if we act now.
This study’s damning findings show the devastating impacts of centuries of colonial and capitalist ransacking of nature. It should be a wake-up call for an overhaul of the Global North’s exploitative relationship with the natural world.
Importantly, it highlights that continuing business-as-usual extractivism risks destroying more precious branches on the ‘Tree of Life’ – making hundreds of diverse species irrevocably extinct. It’s time that rich, industrialised nations largely causing these untimely extinctions took responsibility for this harm.
Feature image via CoolCanuck/Wikimedia, cropped and resized to 1910 by 1000, licensed under CC BY-SA 4.0
