Nearly 30% of world’s animals and plants will be extinct by end of century

By Gwyn Wright via SWNS

More than a quarter of the world’s animals and plants will go extinct by the end of the century, warns a new study that used one of Europe's most advanced supercomputers.

Scientists say 10 percent of plants and animals will disappear by 2050, with the number rising to 27 percent by 2100.

This extinction 'cascade' means that children born today might well be the last generation to see elephants or koalas, the researchers said.

The world is undergoing its “sixth mass extinction event” driven by global warming and changes to land use.

The team says earlier models of extinction trajectories are not particularly useful because they do not take into account co-extinctions, where species go extinct because others on which they depend succumb.

Study author Professor Corey Bradshaw of Flinders University in Adelaide, Australia explained: “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 has become too warm.

“Every species depends on others in some way.”

Until now, researchers have not been able to interconnect species at a global scale in order to work out how much additional loss will take place through co-extinctions.

While earlier studies have examined different aspects of extinctions such as the direct effects of climate change and the loss of habitats on species' fates, these have not been joined together to predict the scale of extinctions.

For the study, academics used one of Europe’s most powerful supercomputers to make synthetic Earths complete with virtual species and more than 15,000 food webs.

The networks were linked by whom eats whom and then climate and land use changes were applied to the system in order to inform future projections.

Virtual species were able to recolonize regions as the climate changed, adapt to changing conditions, go extinct because of global heating or fall victim to an extinction cascade.

Study author Dr. Giovanni Strona from the University of Helsinki said: “Essentially, we have populated a virtual world from the ground up and mapped the result of thousands of species across the globe to determine the likelihood of real-world tipping points.

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

“By running many simulations over three main scenarios of climate until 2050 and 2100- the so-called Shared Socioeconomic Pathways (SSP) from the Intergovernmental Panel on Climate Change (IPCC), we show that there will be up to 34 percent more co-extinctions overall by 2100 than are predicted from direct effects alone.”

Prof Bradshaw said what is even more frightening is that co-extinctions will raise the overall extinction rate of the most vulnerable species by up to 184 percent by the end of the century.

He added: “This study is unique because it accounts for the secondary effect on biodiversity, estimating the effect of species going extinct in local food webs beyond direct effects.

“The results demonstrate that interlinkages between food webs worsen biodiversity loss, to a predicted rate of up to 184 percent for the most susceptible species over the next 75 years.

“Compared with traditional approaches to predicting extinctions, our model provides a detailed insight into variation in patterns of species diversity responding to the interplay of climate, land use and ecological interactions.

“Children born today who live into their seventies can expect to witness the disappearance of literally thousands of plant and animal species, from the tiny orchids and the smallest insects to iconic animals such as the elephant and the koala, all in one human lifetime."

“Despite an appreciation that climate change is a major driver of extinctions globally, the new analysis demonstrates clearly that we have so far underestimated its true impacts on the diversity of life on Earth.

“Without major changes in human society, we stand to lose much of what sustains life on our planet.”

Dr. Stona added that the findings leave “no doubt” that climate change is mainly responsible for most extinctions.