Climate and Biodiversity Crises Are One and the Same

The Two Problems That Are Actually One Problem

In 2023, a team of ecologists and climate scientists led by Hans-Otto Pörtner published a paper in Science that did something unusual. It didn't announce a new species or a new model or a new alarming data point. It said, essentially: we have been thinking about this wrong.

For decades, we have treated climate change and biodiversity loss as separate crises. We have climate conferences and biodiversity conferences. We have climate scientists and conservation biologists. We have carbon budgets and extinction risk assessments. Two different problems, two different sets of solutions, two different buckets of funding.

Pörtner and his colleagues argue this is a category error. The climate crisis and the biodiversity crisis are not two problems that happen to occur at the same time. They are the same problem, expressed through different systems. And treating them separately is not just inefficient. It is dangerous.

What the Paper Actually Found

The authors did not run a single experiment. They did something harder. They synthesized the entire scientific literature on how climate, biodiversity, and human societies interact. Then they asked: what would it actually take to stabilize both systems?

The answer is specific and uncomfortable. To keep the planet livable, we need to limit warming to 1.5°C above preindustrial levels. And we need to effectively conserve and restore functional ecosystems on 30 to 50 percent of land, freshwater, and ocean "scapes" (Pörtner et al., 2023).

Those two numbers are not independent. You cannot hit one without the other. Intact ecosystems store carbon. They regulate water cycles. They buffer extreme weather. They are the planet's natural climate control system. Destroy them, and you make climate stabilization harder. Let the climate destabilize, and you destroy them.

The paper envisions what the authors call a "mosaic of interconnected protected and shared spaces." This is not the old conservation model of walled-off national parks. It is a landscape where intensively used spaces like farms and cities are embedded within a matrix of functional ecosystems. The goal is not to separate people from nature. It is to design human systems that strengthen, rather than weaken, the capacity of both people and nature to adapt (Pörtner et al., 2023).

Why We Have Been Splitting the Wrong Atom

The separation of climate and biodiversity as policy problems has a history. It is not rooted in science. It is rooted in institutional convenience.

In 1992, the Rio Earth Summit produced two treaties: the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity. Two different agreements, two different secretariats, two different sets of negotiations. Countries sent different delegations. Nonprofits organized around different issues. Funding streams bifurcated.

This made sense administratively. It made no sense ecologically.

Consider the Amazon rainforest. It holds billions of tons of carbon. It also holds 10 percent of the world's known species. When you burn it for cattle pasture, you release carbon into the atmosphere and you destroy habitat. That is one action producing two harms. But our policy systems treat those harms as separate. A carbon offset program might pay to protect the forest. A biodiversity fund might pay to protect the forest. But rarely do they coordinate, and sometimes they compete.

Pörtner and his colleagues are not the first to notice this. But their paper is the most comprehensive attempt to map the actual connections and to propose a unified framework. They show that the feedback loops run in both directions. Climate change alters temperature and precipitation patterns, which shifts where species can survive, which disrupts ecosystems, which reduces their ability to store carbon, which accelerates climate change. That is a vicious cycle. But it can also be a virtuous one. Protect ecosystems, and you protect carbon sinks. Protect carbon sinks, and you slow climate change. Slow climate change, and you give ecosystems a chance to adapt.

The Numbers That Should Scare You

The paper is not vague about scale. The authors specify that effective conservation and restoration must cover 30 to 50 percent of the planet's surface. That is not a small number. It is roughly the land area of Asia, Europe, and North America combined.

But "effective" is doing heavy lifting here. The paper is clear that not all protected areas are equal. A "paper park" that exists only on a map does not count. A degraded ecosystem that has lost its functional capacity does not count. The authors are calling for ecosystems that are self-sustaining, that can maintain their biodiversity and their ecological processes without constant human intervention (Pörtner et al., 2023).

This is a different vision from the one that dominates climate policy right now. Much of the current conversation focuses on technological solutions: solar panels, electric vehicles, carbon capture machines. Those tools matter. But the paper argues they are not sufficient. Even if we decarbonize the global economy overnight, we still need functioning ecosystems to stabilize the climate. The machines cannot do what the forests do.

How They Did the Research

The paper is a review, not an original empirical study. But it is a particular kind of review: a synthesis of multiple lines of evidence from different scientific disciplines. The authors drew on climate models, ecological field studies, paleoclimate records, and economic analyses. They looked at how ecosystems have responded to past climate changes, how they are responding now, and what the models project for the future.

The strength of this approach is that it can see patterns that no single study can reveal. The weakness is that it depends on the quality of the underlying studies. The authors are transparent about this. They note where evidence is strong and where it is contested. They do not pretend to have all the answers.

What This Means for How We Think About Solutions

The paper has a roadmap section that is worth reading closely. It is not a list of technologies. It is a list of institutional and governance changes.

The authors argue that we need "interconnected institutions, governance, and social systems from local to global levels" (Pörtner et al., 2023). This is policy language for something simple: the people making decisions about climate and the people making decisions about biodiversity need to talk to each other. They need to share data. They need to coordinate funding. They need to stop working at cross purposes.

One concrete example: agricultural policy. Current subsidies in many countries encourage farmers to clear land and maximize yields. This produces food, but it also destroys habitat and releases carbon. The paper argues for shifting subsidies toward practices that maintain ecosystem function while producing food. Agroforestry, for instance, integrates trees into crop systems. It stores carbon, provides habitat, and can increase yields over time. But it requires different incentives than the ones we have now.

Another example: coastal management. Mangrove forests protect coastlines from storms, store carbon at rates higher than tropical rainforests, and provide nursery habitat for fish. But they are being cleared for shrimp farms and development. The paper argues for protecting and restoring mangroves as a single solution that addresses climate adaptation, climate mitigation, and biodiversity conservation simultaneously (Pörtner et al., 2023).

What the Research Does Not Prove

The paper is ambitious, and it is worth being clear about its limits.

It does not prove that protecting 30 to 50 percent of the planet is politically feasible. The authors acknowledge this is a massive undertaking that would require transforming land use, economic systems, and political institutions. They do not pretend to have a detailed political strategy.

It does not prove that humanity can avoid all the consequences of climate change and biodiversity loss. Even with aggressive action, some warming and some species loss are already locked in. The paper is about minimizing harm, not eliminating it.

It does not resolve the deep tensions between conservation and human development. The authors call for a "mosaic" of protected and shared spaces, but they do not fully specify how to balance the needs of Indigenous communities, small farmers, cities, and wildlife. These are genuine tradeoffs that require local negotiation, not global prescription.

And it does not prove that technological solutions are irrelevant. The paper's argument is that technology alone is insufficient, not that it is useless. We need both decarbonization and ecosystem protection. The question is how to prioritize and integrate them.

The Hidden Assumption That Changes Everything

Underneath the paper's analysis is an assumption that most climate policy does not share. The assumption is that nature is not just a victim of climate change. It is a solution.

This sounds obvious, but it is actually a radical shift. Most climate policy treats nature as something to be saved from climate change, not something that can help save us. The dominant framing is about reducing emissions and adapting to impacts. Ecosystems are seen as casualties, not allies.

Pörtner and his colleagues flip this. They argue that functional ecosystems are our best bet for both mitigation and adaptation. A healthy forest does not just absorb carbon. It also cools the local climate, regulates water flow, and provides food and medicine. A healthy coral reef does not just support fish. It also protects coastlines from storm surge. These are not side benefits. They are the core of what makes a livable planet.

This has implications for how we measure progress. Right now, the primary metric for climate action is tons of carbon dioxide equivalent. That is important. But the paper suggests we also need metrics for ecosystem health: species richness, habitat connectivity, functional diversity. You cannot manage what you do not measure.

What This Actually Means

Here is what changes if you accept the paper's argument:

• ▸Climate policy and biodiversity policy must be designed together, not separately. Any climate solution that damages biodiversity is not a real solution. Any biodiversity solution that ignores climate is incomplete. This means carbon offset projects that plant monoculture tree plantations are not just bad for biodiversity. They are bad for climate, because monocultures are vulnerable to fire, disease, and climate stress. The paper calls for restoring functional ecosystems, not just planting trees.

• ▸The 30x30 target (protecting 30 percent of land and ocean by 2030) is not ambitious enough if it is done poorly. The paper specifies that protection must be "effective" and that restoration must target 30 to 50 percent of scapes. A paper park that exists only on a map does not count. A degraded ecosystem that has lost its functional capacity does not count. Quality matters as much as quantity.

• ▸Agricultural and urban systems must be redesigned as part of the solution, not excluded from it. The mosaic model means that farms and cities are not separate from conservation. They are part of the matrix. This requires different farming practices, different urban design, different supply chains. It is harder than setting aside wilderness. It is also more realistic, because most of the planet is already used by people.

• ▸Local governance matters more than global agreements. The paper emphasizes "interconnected institutions from local to global levels." Global treaties set targets, but implementation happens at the local level. Communities need the authority and resources to manage their own ecosystems. Top-down conservation that displaces people does not work. Bottom-up conservation that empowers people does.

• ▸The cost of inaction is not linear. It accelerates. The feedback loops between climate and biodiversity mean that every year of delay makes the next year harder. Lose a forest, and you lose its carbon storage and its cooling effect. Lose that cooling effect, and the adjacent forest becomes more vulnerable to fire. Lose that forest, and you lose more carbon. The paper is a warning that we are approaching thresholds where these feedbacks become self-reinforcing. The time to act is now, not when the evidence becomes undeniable.

The paper ends with a line that is not poetic but is precise. It calls for "fostering interlinked human, ecosystem, and planetary health for a livable future." That is the goal. The question is whether we can reorganize our institutions, our economies, and our thinking fast enough to achieve it.

The science says we know what to do. The question is whether we can do it together.