Humans almost solely responsible for mammal extinctions in past 126,000 years, study finds

Emma Gatten
·2 min read
The extinction of many species of megafauna, including woolly rhinos, has previously been attributed to climate change -  AFP
The extinction of many species of megafauna, including woolly rhinos, has previously been attributed to climate change - AFP

Human activity was the cause of 96 per cent of mammal extinctions in the past 126,000 years, rather than climate change, according to a new study. 

The arrival of humans to Australia around 65,000 years ago and the Americas some 24,000 years ago caused particular spikes in animal extinctions, according to the study in Science Advances. 

The researchers found similar results in Madagascar and the Caribbean, where animal extinction rates shot up after the arrival of the first humans. 

The study by a team of researchers from Sweden, Switzerland, and the UK predicts as many as 558 species could be lost in the next hundred years, amid the highest spike in extinction rates since non-avian dinosaurs disappeared 66 million years ago.

That compares to just 351 mammal species extinctions since the beginning of the Late Pleistocene 126,000 years ago, although rates have already been rising rapidly, with 80 species lost in the last 1,500 years. 

The conclusion that historical extinctions have been driven by human activity contradicts earlier studies which have suggested that climate change was responsible, in particular for the extinction of megafauna such as woolly rhinos and mammoths 12,000 years ago. 

The scientists compiled a large dataset of fossils and found “essentially no evidence for climate-driven extinctions”, said co-author Daniele Silvestro. 

But the authors of the study, which was published in Science Advances, warned that climate change now poses a unique threat to animal species. 

“Together with fragmented habitats, poaching, and other human-related threats, it poses a large risk for many species,” said Mr Silvestro. 

Current extinction rates are around 1,700 times higher than those at the beginning of the Late Pleistocene, the authors say. 

“Reconstructing our past impacts on biodiversity is essential to understand why some species and ecosystems have been particularly vulnerable to human activities – which can hopefully allow us to develop more effective conservation actions to combat extinction," said co-author Professor Samuel Turvey at ZSL (Zoological Society of London).