Invasive species, commonly known as weeds, along with climate change form a “deadly duo”, posing a danger not only to the environment but also to the Gross Domestic Product (GDP) of countries, according to scientists.

In a report “Invasive Species, Climate Change and Ecosystem-Based Adaptation: Addressing Multiple Drivers of Global Change”, released in the Japanese city of Nagoya during the ongoing U.N. summit on Biodiversity, scientists urged nations to take immediate action against the “deadly duo” to save the world from disaster.

Conducted by the Global Invasive Species Programme (GISP) and funded by the World Bank, the study identifies how invasive species and climate change are linked and looks at what needs to be done to lessen their impact.

The report urges governments to integrate the prevention and management of invasive species into how they respond to climate changes. From a policy perspective, invasive species and climate change have largely been kept separate.

Referring to the ‘deadly duo’, Sarah Simons, Executive Director of GISP, said that “each driver poses an enormous threat to biodiversity and human livelihoods but now, evidence is rapidly emerging which shows that climate change is compounding the already devastating effects of invasive species, resulting in a downward spiral with increasingly dire consequences.”

Invasive species which are also known as “pest” species are the plants or weeds that get out of control and can cause enormous ecological, economic or health problems while threatening many native species with extinction.

According to an estimate, damage from invasive species worldwide totals more than $ 1.4 trillion annually —— that’s five per cent of the global economy. Estimates of economic losses from global climate change are also about 5 per cent of annual GDP.

“Climate change is already receiving significant attention in the research and policy communities,” said Bill Jackson, Deputy Director General of the International Union Conservation for Nature (IUCN), an environment network, which has supported the study.

“But this report shows the need to dig deeper on where climate change interacts with invasive species. The financial costs of not responding should be enough to encourage policy makers to take urgent action,” he was quoted as saying in a statement issued by IUCN.

Examples of the spread of invasive species being linked to climate change include the livestock disease, bluetongue, which in 2007 alone cost in excess of $ 200 million, said the statement.

Similarly, Miconia calvescens, an invasive tree species which increases the risk of landslides when coupled with high rainfall and the fungus, Batrachochytrium dendrobatidis (Bd), thought to have contributed to the massive extinction of primarily tropical frog species.

“Fortunately, we already know many of the actions necessary for offsetting the threat of invasive species to key ecosystem services, such as erosion control and freshwater availability,” said Stas Burgiel, GISP’s Policy Director and lead author of the report.

“Such ecosystem-based approaches are not simply about saving ecosystems, but rather about using ecosystems to help save people and the resources on which we depend,” he added.