Invasive alien species cost the planet £335 billion in 2019 and are an ‘underappreciated, underestimated and often unacknowledged threat’, according to a new report into this global threat to nature.
More than 37,000 alien species have been introduced by human activities to regions and biomes around the world. This conservative estimate is now rising at unprecedented rates.
Invasive species can threaten human food supply, and are one of five main drivers of biodiversity loss, alongside changes in land and sea use, direct exploitation, climate change and pollution.
The recent Kunming-Montreal treaty, with its target of protecting 30% of the planet’s land and sea by 2030, said governments should ‘eliminate, minimise, reduce and or mitigate’ non-native plants and animals.
Despite being recognised as a major threat, the specific impacts of invasive species are poorly understood, the researchers said.
The report has investigated the different types of alien species and how they affect ecosystems, the extent to which they threaten food, human health and livelihoods, how they spread between and within countries, as well as how effective control measures are on international and local scales.
For example, nearly 80% of the documented impacts of invasive alien species on nature’s contributions to people are negative, such as the threats to food supplies.
Options for policies on how to prevent, eradicate and control invasive species are also offered in the report, which was four years in the making at a cost of £1.2m, and put together by 86 experts from 49 countries.
It is published by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) – also known as the IPCC of biodiversity.
‘The rapidly growing threat that invasive alien species pose to biodiversity, ecosystem services, sustainable development and human wellbeing is generally poorly understood,’ said Professor Helen Roy, of the UK Centre for Ecology & Hydrology and co-chairwoman of the report.
‘This authoritative report will make a major contribution to filling critical knowledge gaps, supporting decision-makers and raising public awareness to underpin action to mitigate the impacts of invasive alien species.’