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Climate Change a Trojan Horse for Alien Species Invasion?

Changing climate conditions and the massive invasions of exotic species introduced by human migration and the global economy are two of the biggest factors driving native species and habitats toward extinction. Now a new study finds that the combination of climate change and invasive species is compounding the devastation of ecosystems.

Two of the greatest threats to the natural world–invasive species and climate change–when combined, not only have devastating impacts on the environment but can also cost countries ten per cent of their gross domestic product (GDP), scientists from the Global Invasive Species Programme (GISP) said today.

In a report released in Nagoya, Japan, the researchers urged countries to take immediate action against the “deadly duo,” the International Union for Conservation of Nature (IUCN), said in a news statement.

Deadly Duo, Drivers of Change

GISP called on delegates at the meeting of the United Nations Convention on Biological Diversity, currently being held in Nagoya, to recognize the “deadly duo” as drivers of change.

The study by GISP, supported by IUCN and other conservation organizations, and funded by the World Bank, identifies how invasive species and climate change are linked and looks at what needs to be done to lessen their impact, IUCN explained.


The report, “Invasive Species, Climate Change and Ecosystem-Based Adaptation: Addressing Multiple Drivers of Global Change,” 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, IUCN said.

“The dangers posed by this ‘deadly duo’ cannot be overestimated,” said Sarah Simons, executive director of GISP. “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.”

According to IUCN, estimated damage from invasive species worldwide totals more than U.S.$1.4 trillion annually–five per cent of the global economy. Estimates of economic losses from global climate change are also about five percent of annual GDP.

“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.”

“Climate change is already receiving significant attention in the research and policy communities,” said Bill Jackson, deputy director general of IUCN, “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.”

Examples of Invasive Species Linked to Climate Change

Examples cited by IUCN of the spread of invasive species being linked to climate change include the livestock disease, bluetongue, which in 2007 alone cost in excess of U.S.$200 million; 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.”

Posted by David Braun from media materials submitted by IUCN.

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