Report urges global leaders to address interconnected environmental, social and economic crises

Pamela McElwee, a professor in the Department of Human Ecology at the Rutgers School of Environmental and Biological Sciences, has spent the last 25 years studying human adaptation to global environmental change.

She has served as an adviser on environmental policy to the White House, U.S. Senate and U.S. Environmental Protection Agency. Recently, as co-chair of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), McElwee oversaw the culmination and global adoption of the Nexus Assessment Report.

Released in December in Windhoek, Namibia, the report offers decision makers worldwide a comprehensive assessment of the interplay between biodiversity, water, food, health and climate change and explores more than five dozen potential responses to address issues raised in the study.

McElwee discusses her experience during the report’s finalization and her hopes for its impact.

How do you feel now that the report is finished?

It’s been the honor of my lifetime to lead this effort, and I’m incredibly proud of the team that helped to put this report together. We had 165 authors from 57 different countries and I loved meeting every single one of them to learn from them and work together towards this outcome.

We collectively put three years of effort into this report, which we hope will have significant impacts on policymakers around the world in helping them manage trade-offs between biodiversity, water, food, health and climate change.

It’s a perfect example of the kind of global impact that we want to have at Rutgers, and I hope my involvement highlights the interdisciplinary excellence in research and teaching on environmental issues that we have here.

What does the report say?

Our report is one of the most ambitious scientific assessments ever undertaken on our current environmental, social and economic crises, including biodiversity loss, water and food insecurity, health risks and climate change.

The assessment shows how these crises are all interconnected in ways that make separate efforts to address them ineffective and counterproductive. For example, current approaches to economic activity result in unaccounted for costs and damages to biodiversity, water, health and climate that we estimated cost at least $10 trillion to $25 trillion per year, equivalent to around 25% of global GDP.

The good news is that there are lots of potential solutions that promote synergies to minimize these externalities. Examples include: restoring carbon-rich ecosystems such as forests, soils, mangroves; managing biodiversity to reduce risk of diseases spreading from animals to humans; improving integrated landscape and seascape management; expanding urban nature-based solutions, like green space in cities; and promoting sustainable healthy diets.

The assessment provides a scientific review of which potential policies and actions are most effective and feasible to ensure these integrated co-benefits.

Is the world a different place from when you started to prepare this report three years ago?

Last year was a rough year for multilateral environmental agreements that are supposed to get the countries of the world to cooperate on key ongoing crises. The Convention on Biological Diversity meetings ended up being suspended and unfinished. The Framework Convention on Climate Change meetings ended with no new solutions on climate. And negotiations for a global plastics treaty collapsed with no agreement.

We start 2025 with the new Trump administration pulling out of the Paris Agreement, a treaty on climate change. The administration will likely target other agreements as well. But despite all this, all the countries that are members of IPBES (more than 140, including the U.S. under the previous administration) voted to approve and adopt the Nexus Assessment Report, which is based on sound science and provides a number of potential solutions for tackling these crises.

What recommendations do you expect to be adopted?

Science-policy assessment reports such as ours do not recommend particular courses of action. We assess what the costs and benefits are of different options and let decision makers choose which are most appropriate for their circumstances.

That said, we evaluate over 70 different options that provide co-benefits across biodiversity, water, food, health and climate change, so there are a wide variety of potential steps. Many of these actions are things farmers, consumers, community members and educators can do, and the scale of action for many is locally focused.

That is all good news, given the ongoing lack of clarity about the role of the U.S. federal government on environmental policy. Even if we don’t see action over the next four years at the federal level, there are many things that states and localities can do. For example, I will be speaking on Earth Day to decision-makers in Wilmington, Delaware, about the report, as there is a lot of interest in what they can do at state level and below on biodiversity and climate over the next few years.

What went into preparing this report?

Our report has been more than three years in development, at a total cost of more than $1.5 million. Across seven chapters, we organized teams of authors to assess the scientific literature, such as on current and future trends in and among biodiversity, water, food, health and climate change, and possible options to help policymakers design solutions in more holistic ways across these elements.

We started in early 2022 and met in person three times for the full author team—in Germany, South Africa and Nepal. A smaller group of coordinating lead authors together with myself and my co-chair Paula Harrison [principal natural capital scientist and professor of land and water modelling at the UK Centre for Ecology & Hydrology] met even more times both in person and online to produce a summary for policymakers.

In all, everyone gave a significant portion of their lives over the past three years to ensure we were assessing the best available evidence through robust methodologies, resulting in some clear findings for tackling our interlinked environmental crises.