Why Are So Many Species Disappearing¿

Look at this forest. The trees are still there. Leaves are moving. Light filters through the branches. At first glance, everything looks normal. But here is a question. Can a forest stay green while losing some of its life? When we think about species disappearing, we often imagine one last animal. The last member of a lineage. One final individual somewhere, before silence. But biodiversity loss usually begins long before that final disappearance. Populations shrink, habitats become disconnected, relationships break down, and a species that is still present may already have become far more vulnerable. So why are we losing so many species? What are we really losing? And above all, can we still change some of these trajectories? Let's begin with an essential distinction. A declining population is not an extinct species. A species can live in several regions. It may decline in some, remain stable in others, or disappear locally without becoming globally extinct. Global extinction means that every individual has disappeared. These situations are not interchangeable, but waiting for extinction before taking action would mean waiting Until a return is impossible. Another important distinction, a threatened species is not a species that has already disappeared. In the July 2026 update of its Red List, the International Union for Conservation of Nature recorded around 49,500 threatened species among nearly 176,000 assessed species. The words assessed species are essential. This assessment does not cover every species on the planet. The recorded number of threatened species also depends on progress in assessments. An increase in that total cannot simply be turned into a count of extinctions during the year. But biodiversity is not just a list of species. It includes diversity within species, diversity between species, and the diversity of ecosystems. In other words, counting names is not enough. We also need to understand what allows these organisms to live together. Why are those conditions deteriorating? The Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services identifies five major direct pressures. Changes in land and sea use. Direct exploitation of organisms. Climate change. Pollution. An invasive alien species. Their importance varies between regions and ecosystems. In particular, climate change alone cannot explain the entire biodiversity crisis. To understand these pressures, let's follow a landscape. Imagine a continuous habitat. Then part of it is converted. A road cuts through it. Other developments divide what remains. On a map, there are still green spaces. But for the organisms living there, those spaces do not necessarily form a usable, connected habitat. That is why these are two different questions. How much area remains, and under what conditions can organisms still live there? Now consider direct exploitation. Problems arise when harvesting exceeds what populations can sustain over time. At sea this means looking at fishing, the species involved, and the conditions in which they are caught. An activity cannot be judged by its name alone. We must examine its intensity, its location, and its effects. The same care is needed for other pressures. Which pollutants? At what concentrations? For how long? Which introduced species? In which environment? With what consequences? Not every species arriving from elsewhere becomes invasive, and not every species responds in the same way to environmental change. A scientific explanation must preserve these distinctions. Climate change adds another challenge. It changes the conditions organisms experience, but it acts in landscapes that have already been transformed. Finding a suitable environment also depends on being able to reach it. A road, an urban area, or a degraded habitat may then matter as much as distance. This is where pressures meet. We might like to attribute each decline to a single cause. It would be simpler, one threat, one solution, one result. But in the field, several constraints may act together. Protecting a species, therefore, requires understanding its particular situation, rather Rather than applying a universal recipe. We also need to look at organisms we think about less often. Plants, fungi, and invertebrates. Biodiversity policy cannot focus only on spectacular animals. A species' media visibility is not a measure of its ecological importance. Behind these pressures lies another question. Why do we keep degrading environments we depend on? In 2026, a new assessment by the International Biodiversity Science Policy Platform examines precisely the links between business and biodiversity. Its central finding is that all businesses depend on nature and have impacts on it, directly or indirectly. An activity may depend on raw materials, water supplies, or the regulation of environmental conditions, even when that dependence is barely visible in its final product. This changes the question. It is not only about protecting a few spaces alongside the economy. We must also examine how the economy uses and transforms environments. For each decision, several questions help. Can we avoid degrading this habitat? Can we produce differently? Are impacts measured in the right place? Who benefits from the activity, and who bears the consequences? Responsibilities differ, and so do the means of action. A company, a government, a local authority, and a consumer do not have the same levers. Turning commitments into action is central to the Biodiversity Conference COP17 in Yerevan, Armenia, in October 2026. The conference is due to examine the first collective review of progress in implementing the Kunming Montreal Global Biodiversity Framework. This framework provides a common direction, but setting a direction and achieving results are different steps. To assess progress, we must look at actions, resources mobilized, and observable changes. Take the target to conserve at least 30% of terrestrial and inland water areas and of marine and coastal areas by 2030. It is often reduced to one number, 30%, but the framework also calls for effective conservation, representative and connected areas, and equitable governance. Drawing a boundary on a map is not enough. We need to know what the area protects, how it is managed, and how the rights and knowledge of indigenous peoples and local communities are taken into account. A protected area does not automatically mean effective protection. Can a species situation still improve? Yes. The numbat, a small Australian marsupial, provides an example. In its July 2026 assessment, the International Union for Conservation of Nature reported an improvement in its status after decades of conservation. Controlling introduced predators, conservation breeding, and moving animals to suitable sites have contributed to its recovery, but this improvement still depends on continued efforts. the case shows two things a trajectory can change and a result may need to be maintained for a long time now for our evidence check are human pressures on biodiversity well established yes are all species declining everywhere at the same rate for the same reasons no is a threatened species doomed to disappear no and does announcing protection prove an improvement no it does not Scientific rigor means holding these ideas together, recognizing the seriousness of the problem without erasing differences between situations, recognizing successes without turning them into guarantees. Let's return to our forest. To understand its future, we must look beyond its color. Which species still live there? Can they reproduce? Do their populations remain are the conditions they need to persist being preserved. This is what protecting life means. We are not just losing names from an inventory. We risk losing evolutionary histories, relationships, and possibilities for recovery. Protecting a species is not simply keeping its last representative alive. It means preserving the conditions that allow it to keep living.