Flinders University: Extinction cascades may decimate world biodiversity by 2050

A new tool developed by European and Australian scientists enabling unparalleled modelling of interconnected species loss shows cascading extinctions are unavoidable, and that the Earth will lose some 10% of its animals and plants by 2050, rising to 27% by 2100.

Using one of Europe’s most-powerful supercomputers, European Commission scientist Dr Giovanni Strona also of the University of Helsinki and Professor Corey Bradshaw of Flinders University used the tool to create synthetic Earths complete with virtual species and more than 15,000 food webs and examine extinction mechanisms, to predict the interconnected fate of species that will likely disappear from the ravages of climate and land-use changes.

The tool presents a grim prediction of the future of global diversity, confirming beyond doubt that the world is in the throes of its 6th mass extinction event.



Animation showing predicted co-extinctions under a high emission climatic scenario SSP5-8.5 (G Strona, European Commission)


The two scientists say past approaches to assessing extinction trajectories over the coming century have been stymied by not incorporating co-extinctions — that is, species that go extinct because other species on which they depend succumb to climate change and/or changes to the landscape.


‘Think of a predatory species that loses its prey to climate change. The loss of the prey species is a ‘primary extinction’ because it succumbed directly to a disturbance. But with nothing to eat, its predator will also go extinct…a ‘co-extinction’. Or, imagine a parasite losing its host to deforestation, or a flowering plant losing its pollinators because it becomes too warm. Every species depends on others in some way,’

– Professor Corey Bradshaw.

Until now, researchers have not been able to interconnect species at a global scale to estimate how much additional loss will occur through co-extinctions. While there are many excellent analyses examining distinct aspects of extinctions, such as the direct effects of climate change and habitat loss on species’ fates, these aspects are not necessarily stitched together realistically to be able to predict the scale of extinction cascades.

Strona’s and Bradshaw’s solution to this problem was to build a massive virtual Earth of interconnected species networks linked by who eats whom, and then apply climate and land-use changes to the system – from best case to worse case scenarios – to inform future projections.

The virtual species could also recolonise new regions as the climate changed, could adapt to some extent to changing conditions, could go extinct directly from global change, or could fall victim to an extinction cascade.

‘Essentially, we have populated a virtual world from the ground up and mapped the resulting fate of thousands of species across the globe to determine the likelihood of real-world tipping points,’ explains Dr Strona.

‘We can then assess adaptation to different climate scenarios and interlink with other factors to predict a pattern of coextinctions.