June 9, 2023

Near the end of 2022, representatives from nearly every nation on Earth gathered in Montreal to negotiate a 30-year blueprint on how to save the world’s biodiversity. The meeting, called COP15, had been delayed for several years because of the COVID pandemic, but the delegates reached an agreement that promises a potential breakthrough for preserving nature, including an ambitious goal to better protect an area covering 30 percent of the world’s land and sea. Yet one crucial issue the representatives to this meeting failed to agree on is how to link efforts to protect biodiversity to efforts to address climate change.

From a policy perspective, treating the problems of a warming planet and loss of nature separately makes little sense. We already know that species and ecosystems are at risk from rising temperatures. Many plants and animals face physiological stressors when their surroundings warm or are hit with more extreme events, leading them to shift their habitats or seek other food supplies. These changes in turn can lead to population declines, or in worst-case scenarios, extinction. Species that cannot move to escape climate change are particularly at risk; an obvious example are corals, rooted in place while ocean waters warm around them. Tens of billions of U.S. dollars in global economic damages are likely as coral reefs continue to degrade, including the loss of important nutritional fish stocks.

At the same time, biodiversity loss affects the climate system; ecosystems play major functional roles in how carbon and water cycle between land, oceans and the atmosphere. When these ecosystems are degraded, their climate-regulating influences on local, regional and global temperatures also suffer. The current state of the Amazon is a case in point: scientists fear that losses of ecosystem resilience from deforestation combined with rising temperatures have created a threshold from which these rich forests may not recover, threatening to leave the region in a state of perpetual drought. Several colleagues and I just published a paper arguing that ecosystems are nearing such biodiversity-climate thresholds, but that urgent attention to managing multifunctional landscapes will help us avoid the worst risks.

If policy makers and diplomats do not consider climate change and biodiversity as two sides of the same coin, they risk duplicating efforts that draw on finite resources and money. Siloed efforts can also be counterproductive, such as sacrificing biodiversity for climate solutions, as has happened when poorly planned renewable energy installations expand into environmentally sensitive lands. Instead, we must tackle climate change and the loss of biodiversity together, which requires a new way of designing and carrying out policies that treats environmental issues as interconnected. If we do not include understanding of the interplay between climate and biodiversity across all our environmental and economic actions, we run the risk of worsening global warming while also losing species and ecosystems.

It seems hard to believe that climate and biodiversity are still treated separately, given that images like starving polar bears on melting ice floes have brought increased attention to these connections. But our policies still lag far behind, and because of that we won’t be prepared to resolve other future problems far worse than the loss of a single species, even one as charismatic as the polar bear.

As one objective lesson, many wildlife diseases are worsening as a result of the combined effects of climate change, which can expand the ranges of vectors like ticks and mosquitoes, and habitat fragmentation, which pushes animals into smaller concentrated areas where they can be especially vulnerable to an epidemic. Brain worm is one such disease; this parasitic nematode spreads via a host, white-tailed deer, which are currently expanding farther northward in the U.S. as temperatures warm. While brain worm is harmless to deer, it causes an excruciating death for moose, and declines in moose populations are already affecting subsistence hunting among some Indigenous communities in the Great Lakes region. Yet there is no comprehensive approach to tackle climate-driven disease expansion in the U.S. at present.

Addressing a problem like this in an integrated manner would seem an obvious solution, but figuring out the best way to do it has been hard. Many countries have one ministry that focuses on climate (often energy or economic institutions), while another deals with biodiversity. Both the Convention on Biological Diversity and the Framework Convention on Climate Change are organized by the United Nations, but their gatherings are held separately, what they ask their participating countries to commit to is different, and their approaches to common elements such as reporting and enforcement do not align. Everyone knows that we need to integrate these two institutions, but in hammering out the details, things always seem to fall apart.

Such was the case in the COP15 meeting late last year, when a side agreement on biodiversity and climate change that was supposed to signal support for joint work collapsed after days of protracted arguments. Even though the text had been in development since 2019 and stressed the strong scientific foundations for linking climate and biodiversity, by the end of the meeting, it was whittled down to only a terse paragraph postponing a decision until 2024. How did we go from a call for cooperation to kicking the can down the road?

Part of the story is the continuous conflict between developed and developing countries over the cost of protecting ecosystems and reducing carbon emissions and who should be most responsible. Unlike climate, where richer nations create the most greenhouse gas pollution, biodiversity is concentrated in developing countries, and there is tremendous economic pressure to exploit these ecosystems. At the same time, as in the climate negotiations, poorer nations want the Global North to fund the costs of protection and mitigation, and to share in the blame for the loss of biodiversity.

Another conflict was over “nature-based solutions” as a possible remedy; the label is increasingly given to measures that use ecosystems to help buffer extreme events and to sequester carbon. Nature-based solutions have rapidly expanded in recent years, spurred in part by a study in 2017 that suggested conserving and expanding forests, restoring wetlands, and protecting peatlands could provide over one third of the carbon sequestration needed by 2030 to stabilize temperatures. The European Union was the strongest advocate for a robust biodiversity and climate change statement at the Montreal meeting and argued in favor of nature-based solutions as a panacea to many ills. But some developing countries see this concept as a possible Trojan horse requiring the Global South to bear the burdens of protecting ecosystems while the Global North continues to pollute with fossil fuels.

There is some truth to these concerns, as evidenced by countries and companies rushing to issue “net-zero” pledges by using tree planting or other ecosystem-based measures to offset their carbon emissions, rather than by fully decarbonizing their production and supply chains or shifting away from fossil fuels. Developing countries rightly worry that the costs of this misguided approach will fall on their shoulders even though they did little to create the problem in the first place.

Sadly, this impasse is creating even greater challenges for the future. While the vision of expanded protected areas in the new biodiversity agreement has been lauded, static and geographically bounded protection zones are increasingly vulnerable to climate impacts. Species moving away from higher temperatures may no longer be within the boundaries originally set up to conserve them, and thus protected areas cannot be the only solution; we will need to supplement these efforts with climate-specific additions, like conservation corridors for migrating animals, or revised laws for managing species that acknowledge they are moving to higher elevations or cooler waters.

Further, while policy failures to address climate and biodiversity together puts each at risk, the outcomes are especially worrisome for biodiversity. While most polices aimed at conserving and restoring species and landscapes are positive for climate efforts, such as increased protection for ecosystems, which improves natural and social resilience to extreme events, the same cannot be said for climate policies and investments. If they are not managed well, they may have negative impacts on biodiversity. For example, using a large area of land to produce biofuels from corn or other crops in an attempt to reduce dependence on fossil fuels threatens natural habitats, while exploitation of the deep seabed for minerals needed for new energy technologies like electric cars could lead to degradation of marine ecosystems.

In light of these diplomatic and policy failures, we need a new vision to address the ways climate change and biodiversity loss have irrevocably altered the composition of life on our planet. A path forward would require the equivalent of a biodiversity and climate “impact statement” for all decision-making: How will policies, programs and management affect both issues, and how can solutions incorporate both elements? Our end goal should be to “live in harmony with nature” as called for by the Convention on Biological Diversity. Such a nature-positive future would ensure we have the heathy ecosystems we need to support both human and nonhuman life within a stable climate on our irreplaceable planet.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.

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