Summary

The authors utilized global and regional damage cost data (i.e., reported economic losses) for invasive species and natural hazards to compare the total costs of biological invasions with hazards of societal concern, including storms, earthquakes, flood, drought, and wildfire. They also examined temporal trends among biological invasion and natural hazard costs to compare their rates of change. Whereas the impacts by individual invasive species often accrue gradually, the collective impacts of biological invasions over time are massive and the authors found that globally between 1980 and 2019 (~40 years), economic losses from biological invasions were of similar magnitude to natural hazards (e.g., $1,208.0 billion $US for invasions against $1,913.6 bn for storms and $1,139.4 bn for earthquakes). Alarmingly, the costliest biological invasion rankings compared to natural hazards were found in the Pacific and Oceania region, an area that is already disproportionately impacted by climate-induced hazards. Although damages from biological invasions have been shown to be high, societal concern has been insufficient to warrant adequate management investment by decision makers.

Management Implications

• Biological invasions are not often thought of as a type of natural disaster or hazard (e.g., floods, earthquakes, wildfires), but they are comparable in cost and reflect an enormous and increasing burden on societies worldwide.
• The damage cost of biological invasions is increasing at a faster rate than the cost of many natural hazards, which highlights the growing need for proactive responses.
• Countries and communities take measures to prevent or reduce the impacts of natural hazards because their costs are deemed unacceptable. Given the comparable – or even greater – damages that biological invasions pose, the same precautionary approach should be applied.

Take Home Points

• Damage costs from biological invasions are similar in magnitude to acute natural hazards such as storms, floods, wildfire, and earthquakes. But unlike many natural hazards, the human-mediated movement of species can be slowed or prevented.
• Global biological invasion costs ranked second only to storms and increased by 702% over the last four decades. In the U.S., the percentage increase in biological invasions damage costs was more than twice that of all natural hazards.
• In Oceania & the Pacific region, the damage cost of biological invasions over the last four decades far exceeded the cost of all other natural hazards in the region and was more than the sum of all other natural hazards combined.
• The past management of biological invasions has rarely been proactive and is often delayed, with a focus on more costly efforts with a lower chance of success after an invasion has already occurred. This study points towards the increasing cost effectiveness of proactive management such as strengthening biosecurity to prevent the introduction of invasive species.

Summary

A subcommittee of the Invasive Species Advisory Committee (ISAC) conducted a review and gap analysis of 26 U.S. federal Climate Change Adaptation Plans for references to invasive species and how they affect climate adaptation processes and goals. The plans were mandated by U.S. Executive Order No. 14008 (Tackling the Climate Crisis at Home and Abroad, 2021) to enhance the nation’s resilience to climate change, and the subcommittee was specifically interested in identifying areas where agencies and departments could strengthen their climate objectives by considering how invasive species could impact them.

Results

Of the 26 plans reviewed, only 8 directly referenced invasive species and their impacts. And of those 8, just 4 (Departments of Interior, Agriculture, Commerce, and Defense) meaningfully linked invasive species as a threat to climate preparedness and resilience efforts. Results from the gap analysis were used to create five recommendations for integrating invasive species into the federal government’s climate adaptation planning and processes. Specifically, to ensure that climate adaptation goals are met, agencies should:

• Incorporate invasive species into their federal climate change adaptation guidance.
• Increase support for networks and programs, like the Regional Invasive Species and Climate Change (RISCC) Management Networks, that are already working at the intersection of climate change and invasive species.
• Integrate invasive species science and prevention into climate-related treaties, agreements, conventions, and policy.
• Ensure that Early Detection, Rapid Response (EDRR), and safeguarding strategies are informed by the best available climate science.
• Increase investments in long-term invasive species management.

Take Home Points

• Invasive species pose significant challenges to achieving U.S. federal climate adaptation preparedness and resilience goals.
• Failing to account for the detrimental impacts of invasive species will slow or even prevent U.S. agencies and departments from meeting climate adaptation goals. On the other hand, successful invasive species prevention and management benefit biodiversity conservation, economies, human health, and more, while also building resilience to the impacts of climate change.
• Although they were developed based on federal plans, the priority actions recommended by this paper may be applicable in other jurisdictions, such as for U.S. states developing climate action plans (33 U.S. states have released a plan as of 2024).

The conference provided a unique setting where leading legal scholars came together with research scientists to discuss a wide range of pressing topics covering ocean threats, governance, science, and solutions. The week started with a visit to the CRIOBE International Research Station (pictured below), where participants heard from marine research stations across the Pacific and PI Dr. Victoria Keener gave a presentation on the current trends and impacts of climate change in the Pacific region, providing the climate background and context for working across science and policy spaces for the week ahead.

Later in the week, at UC Berkeley’s Gump Station, Project Specialist Chelsey Bryson gave a presentation on the opportunities and challenges of the Green Climate Fund in the Pacific as part of a larger discussion about governance and funding opportunities. Chelsey was also one of three rapporteurs, who presented the key themes of each day at the end of the meeting, such as access to scientific information and data, equity in community involvement, and regional engagement. From there, participants decided on goals and next steps for PIMSA.

On the last day, participants were given a tour of the nearby cultural and community center and heard from Hinano Teavai-Murphy, the Cultural Director of the Tetiaroa Society, before sharing a delicious last local Tahitian meal together.

Communications Manager Krista Jaspers happily tagged along for the week as well, eager at the chance to dive in Moorea’s crystal-clear waters. After a week of fruitful meetings, Chelsey and Victoria joined her on tour to swim with humpback whales on the south side of the island, where the team was greeted by a curious humpback calf – a powerful and welcome reminder of why we are dedicated to this work.