The Marais Poitevin, a wetland area in western France, was designated as a protected site in 1979 to preserve its unique ecosystem. However, despite this protection, the region's peat — a type of organic soil formed over thousands of years — has been drying out over the decades. This drying has raised concerns because peatlands normally act as carbon sinks, absorbing carbon dioxide from the atmosphere. When peat dries, it begins to release stored carbon instead, contributing to climate change. Scientists are now proposing that rehydrating the area could help restore its ability to trap carbon. In the late 1970s, the Marais Poitevin faced serious threats from agricultural practices, such as drainage and land consolidation, which led to the loss of wet meadows and the expansion of cereal farming. To address this, the French government classified the area to protect its ecological diversity. However, the legal protection did not ensure the maintenance of the water levels that are essential for the survival of the peat. Over time, changes in water flow and management have led to a gradual drying of the peatlands, undermining the very ecosystem that the protection was meant to preserve. Peatlands are unique ecosystems that rely on constant waterlogging to maintain their structure and function. When water levels drop, even slightly, the balance is disrupted. Peat is formed through the slow decomposition of plant matter in an oxygen-poor environment. This process traps carbon in the soil. However, when the soil dries, oxygen comes into contact with the organic matter, causing it to oxidize. This releases carbon dioxide into the atmosphere and leads to the gradual disappearance of the peat, causing the land to sink. The drying of peatlands not only neutralizes their role as carbon sinks but also transforms them into significant sources of greenhouse gas emissions. A healthy peatland absorbs more carbon than it releases, but a dried one can emit carbon for years until the organic matter is completely consumed. This makes degraded wetlands some of the most damaging ecosystems in terms of climate impact, despite their relatively small area. The Marais Poitevin is an example of a larger global issue, as drained peatlands contribute significantly to land-use-related emissions worldwide. To address this, some land managers are exploring solutions such as rewetting dried peat areas. This involves restoring water levels to stop the oxidation of organic matter and, over time, allow the peatland to resume its role as a carbon sink. However, this process requires careful planning and collaboration with local farmers, authorities, and other stakeholders. The case of the Marais Poitevin underscores the need to protect not just the legal status of ecosystems, but also their fundamental ecological conditions. It also raises the question of how many other peatlands in France — and around the world — are experiencing similar, unnoticed degradation.