As global temperatures rise from the burning of fossil fuels, researchers and policymakers have proposed solutions like installing renewable energy, replacing gasoline-powered cars with electric ones, and developing technology to suck carbon out of the air. But these policies often address climate change in isolation — without regard for other pressing issues like a decline in biodiversity, the contamination of freshwater sources, and the pollution of agricultural soils.
A new report released Tuesday by the United Nations’ expert panel on biodiversity makes the case for a different approach based on addressing the “nexus” between two or more out of five essential issue areas: climate change, biodiversity, food, human health, and water. Such an approach is not only more likely to help the world meet various U.N. targets on biodiversity, sustainable development, and climate mitigation; it’s also more cost-effective.
“We have to move decisions and actions beyond single-issue silos,” said Paula Harrison, a professor of land and water modeling at the U.K. Centre for Ecology and Hydrology and a co-chair of the report, in a statement. Other scientific reports have studied the interlinkages between two or three of these issues, but she told reporters on Tuesday that this latest report is the “most ambitious” to date.
The new report was the result of three years of work of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, or IPBES, an expert body that’s analogous to the United Nations’ Intergovernmental Panel on Climate Change, which periodically assesses the state of the science on global warming.
The report centers on biodiversity — that’s the IPBES’s remit, after all — describing how the variety of life on Earth is “essential to our very existence.” But it goes out of its way to show how rapidly accelerating biodiversity loss is both contributing to and being exacerbated by other crises. Climate change, for instance, is making some habitats inhospitable to their erstwhile animal populations, while the loss of those populations can have impacts on freshwater availability and carbon storage. The five interlinking issues were selected by representatives of the 147 IPBES’s member countries.
Meanwhile, solutions that focus on just one issue may have detrimental effects on other elements. Pete Smith, a professor of soils and global change at the University of Aberdeen in the United Kingdom, gave the example of bioenergy with carbon capture and storage, or BECCS, a climate solution in which crops are grown to draw CO2 out of the air and then burned to generate energy. The resulting greenhouse gas emissions are captured and stored in rock formations, with the aim of removing them from the carbon cycle permanently.
The problem, Smith said, is that to implement this process on a large scale would require vast tracts of land that might otherwise have been used to grow food crops — so BECCS can unintentionally harm food security. Devoting land to single-variety crops can also use up lots of water and jeopardize biodiversity.
“When you just focus on climate change,” he told Grist, “you might end up with some solutions that damage other elements of the nexus.”
In other scenarios, it’s not the solution itself that’s problematic; it’s the way it’s implemented. Planting trees, for example, can be done in consultation with local communities and taking into account unique ecosystem needs. Or, as Smith described, a big company seeking to generate carbon credits could evict Native peoples from their land and start a plantation of fast-growing, nonnative tree species.
The latter situation might benefit climate change in the narrowest sense, Smith said, but “with a whole bunch of negative impacts on people, on health, on water.”
The assessment finds that, between 2001 and 2021, every one of the five issues analyzed has been damaged by factors including urbanization, war, and growing per capita consumption — except for food availability. That could be explained by a kind of decision-making the report describes as “food first,” in which more food is grown to benefit human health at the expense of biodiversity, freshwater availability, and climate change.
Decision-making built solely around climate change or conservation could be similarly counterproductive, the report says, based on an analysis of 186 future scenarios crafted from 52 scientific studies. The most promising alternative is a “nature-oriented nexus” focused on all five target areas, emphasizing “strong environmental regulation, sustainable agricultural practices, lower rates of global per capita consumption, and strong development of green technologies.”
More than 160 scientists from 57 countries contributed to the report, which was formally adopted this weekend at IPBES’s annual conference in Windhoek, Namibia. During a press conference on Tuesday, the authors said they were ending the year “on a high note for multilateralism,” in contrast to the stalemates that defined other intergovernmental negotiations in 2024, like the global plastics treaty and the climate conference in Baku, Azerbaijan.
In addition to the nexus report, IPBES member states also approved a report on the “transformative change” that is needed to address global crises connected to biodiversity, including climate change. Notably, that report says that “disconnection from and domination over nature and people” is at the root of toxic chemical pollution, deforestation, the burning of fossil fuels, and other causes of climate and environmental degradation.
Kiara Worth / IISD/ENB
Both reports highlight the need to address the inequitable concentration of wealth and power and the prioritization of short-term material gains in order to “prevent triggering the potentially irreversible decline and projected collapse of key ecosystem functions.”
“Right now, our economic and financial system is not fit for purpose; it does not value nature,” Pamela McElwee, a professor of human ecology at Rutgers University and a co-chair of the nexus report, told reporters on Tuesday.
The nexus report finds that $7 trillion a year in public subsidies and private financial incentives go toward activities that directly damage the five issue areas. Only $200 billion — less than 3 percent of that total — is spent directly on improving biodiversity.
Because the nexus report was requested directly by the governments of IPBES’s 147 member countries — among them, China, India, Indonesia, Nigeria, Pakistan, the United States, and most of Europe — the scientists who contributed to it are hopeful that their recommendations will be adopted by policymakers. In the report, they highlight 71 cross-cutting responses to interlinked global problems, ranging from reducing plastic pollution to conserving wetland ecosystems to providing universal health coverage.
Smith, who is a soil researcher and has also contributed to reports of the Intergovernmental Panel on Climate Change, said working on the report has changed his own outlook. “I’ve tried to apply the nexus thinking on a couple of projects on how climate change affects the food system, and people in disadvantaged communities,” he said. “All of these things are leading me to take a broader, less siloed view than I would have done 10 years ago.”
Previous IPBES reports have shown how biodiversity is “declining faster than at any time in human history.” At the group’s next conference in 2025, it’s expected to present a new assessment of businesses’ impact and dependence on biodiversity, and IPBES plans to release its second global assessment of the state of biodiversity in 2028.
