Under the Brazilian savannah, several meters deep, the carbon trapped in the soil of the Cerrado dates back on average to over 11,000 years ago, with peaks up to 20,000 years old. This immense tropical savannah covers approximately 26% of the Brazilian territory, is home to over 12,000 plant species and – as revealed by a study published in New Phytologist led by researcher Larissa Verona — one of the largest carbon sinks on the planet. Yet he remains almost absent in the global environmental debate, crushed by the shadow of the Amazon.
The carbon that cannot be seen
In the Cerrado wetlands, carbon accumulates in the soil at an average density of about 1,200 tons per hectare: four to eight times more than in mature tropical forests, including the Amazon. To obtain these numbers, the researchers extracted soil cores several meters deep in seven areas of the savannah, finding organic matter that had slowly accumulated over millennia, in conditions that no longer exist today. If released, that carbon cannot be reabsorbed in a timely manner. No reforestation, no trapping technology could compensate for it. The damage would be irreversible.
The paradox of the dry season
The areas with the highest carbon density cover approximately 16.7 million hectares (less than 8% of the biome) but represent a critical node in the global climate system. A particularly fragile issue: around 70% of greenhouse gas emissions occur during the dry season. With global warming intensifying drought and aridity, a trap is opening: less water means more CO₂ released, higher temperatures, further dried out soils. A circle that tightens on itself.
The hidden cost of protecting the Amazon
The Cerrado is today one of the most advanced fronts of Brazilian industrial agriculture. Soya, livestock and monocultures often advance without the restrictions applied to the Amazon forest, which enjoys incomparably stronger regulatory protection. Verona formulates the most uncomfortable paradox directly: sacrificing the Cerrado to protect the Amazon means eliminating part of the water that flows towards the forest and contributes to keeping it alive. The two ecosystems are connected: the Cerrado feeds major water basins that also support the rainforest. Defending one while abandoning the other is equivalent to removing the foundations of what you want to save. In Brazil there are rules for the protection of wetlands, but not for the water resources that maintain them. A void that is not a technical detail: it is the difference between protecting an ecosystem and protecting only its surface.
The giant we cannot afford to ignore
What the Verona study asks is not to replace the Amazon on the global environmental agenda, but to broaden our gaze to what is around it and supports it. Beneath the surface of a little-photographed and little-told savannah, in layers of earth accumulated over twenty thousand years, there is a balance that no international agreement could rebuild once lost. The giant is invisible. But the consequences of its collapse would not be.
