UNITED NATIONS
By Manuela Andreoni
The New York Times
Thousands of invasive species introduced to new ecosystems around the world are causing more than $423 billion in estimated losses to the global economy every year by harming nature, damaging food systems and threatening human health, a wide-ranging scientific report published last week has found.
The costs have at least quadrupled every decade since 1970, according to the report, which was based on 2019 data. Researchers warned that the cost figures were conservative estimates because of the challenges in accounting for all effects.
Over the past few centuries, humans have intentionally and unintentionally introduced more than 37,000 species to places outside their natural ranges as the world has become more interconnected, the assessment said. More than 3,500 of those are considered invasive because they are harmful to their new ecosystems.
Invasive nonnative species were a major factor in 60% of recorded extinctions of plants and animals, according to the report, which was produced by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services for the United Nations. It expands on a sweeping 2019 report by the same panel, which found that as many as 1 million plant and animal species are at risk of extinction.
“We are seeing unprecedented increases in the numbers of alien species worldwide,” Helen Roy, an ecologist and one of the leaders of the new study, said in an interview. “It’s about 200 new alien species every year. And, yes, with those kinds of numbers, we will also see the impacts increasing.”
The report is the most exhaustive look yet at how invasive nonnative species are driving biodiversity loss.
Some species are relocated by global forces such as wildlife trade and international shipping. Zebra mussels, for instance, are an invasive species that has driven local mussels to the brink of extinction in the Great Lakes and forced power plants to spend millions unclogging water intakes.
They probably arrived in North America on cargo ships from Europe in the 1980s.