Alien species to increase by 36% worldwide by 2050

Alien species to increase by 36% worldwide by 2050 - University College London

The number of alien (non-native) species, particularly insects, arthropods and birds, is expected to increase globally by 36% by the middle of this century, compared to 2005, finds new research by an international team involving UCL.

Published in Global Change Biology, the study also predicts the arrival of around 2,500 new alien species in Europe, which translates to an increase of 64% for the continent over the 45-year period.

two egyptian geese — Egyptian goose (Alopochen aegyptiaca) originally from Africa and now established in Central and Western Europe. (Credit: Professor Tim Blackburn, UCL)

The research team led by the German Senckenberg Biodiversity and Climate Research Centre hope it should be possible to reduce this number with stricter biosecurity regulations.

Alien species are those that humans have moved around the world to places where they do not naturally occur. More than 35,000 such species had been recorded by 2005 (the date of the most recent comprehensive global catalogue). Some of these aliens can go on to become invasive, with damaging impacts to ecosystems and economies. Alien species are one of the main drivers of extinctions of animals and plants.

Co-author Professor Tim Blackburn (UCL Centre for Biodiversity & Environment Research and the Institute of Zoology, ZSL) said: “Our study predicts that alien species will continue to be added to ecosystems at high rates through the next few decades, which is concerning as this could contribute to harmful biodiversity change and extinction.

“But we are not helpless bystanders: with a concerted global effort to combat this, it should be possible to slow down or reverse this trend.”

The study identifies high levels of variation between regions. The largest increase is expected in Europe, where the number of alien species will increase by 64% by the middle of the century. Additional alien hotspots are predicted to include temperate latitudes of Asia, North America, and South America. The lowest relative increase in alien species is expected in Australia.

Europe will also see the largest increase in absolute numbers of alien species, with around 2,500 new aliens predicted.

Read the paper: Seebens, H, Bacher, S, Blackburn, TM, et al. Projecting the continental accumulation of alien species through to 2050. Glob Change Biol. 2020; 00: 1– 13. doi: 10.1111/gcb.15333 (open access)