The conversion of Brazil's native biomes into agricultural areas has resulted in an estimated loss of 1.4 billion tons of soil carbon. This amount is equal to the emission of 5.2 billion tons of carbon dioxide (CO₂) equivalent, a unit of measurement used to standardize the emission of different greenhouse gases, and was calculated based on data collected from studies conducted over the past 30 years.
These findings are from a study published in the journal Nature Communications by researchers from the Luiz de Queiroz School of Agriculture at the University of São Paulo (ESALQ-USP) and the State University of Ponta Grossa (UEPG), as well as Embrapa Agricultura Digital, one of the decentralized units of the Brazilian Agricultural Research Corporation (EMBRAPA).
The study was conducted as part of the Center for Carbon Research in Tropical Agriculture ( CCARBON ), a FAPESP Research, Innovation, and Dissemination Center ( RIDC ) based at ESALQ-USP and coordinated by Carlos Eduardo Pellegrino Cerri , who is also an author of the article.
The good news is that the researchers estimate that "recarbonizing" about one-third of the country's agricultural land would be sufficient to meet Brazil's Nationally Determined Contribution (NDC) under the Paris Agreement, which aims to reduce greenhouse gas emissions by 59% to 67% compared to 2005 levels by 2035.
This goal could theoretically be achieved using sustainable techniques, such as crop rotation, no-till farming, and integrated systems like ICLF (Integrated Crop-Livestock-Forest). Another potential solution is the restoration of degraded pastures, which cover 20 million hectares in the Atlantic Forest alone.
"The main objective of this study was to estimate the carbon debt of Brazil's soils. In addition to arriving at this overall figure, we calculated how much each biome accumulates and how much carbon is lost when a natural area is converted to agriculture, as well as which agricultural practices conserve more or less carbon in the soil," summarizes João Marcos Villela , the first author of the study and a researcher at ESALQ-USP supported by FAPESP .
The estimates were derived from an analysis of Brazil's largest soil carbon database, which the researchers compiled from 4,290 records spanning 372 studies published over the past 30 years. The study covered all Brazilian biomes and included both areas of natural vegetation and agricultural land.
The researchers expect the results of the study to guide public policies and private-sector initiatives to promote sustainable farming practices and inform the carbon credit market with data on Brazilian carbon stocks.
Best practices
To calculate greenhouse gas emissions, the CO₂ equivalent metric is used to standardize different gases into a single unit of measurement. In this case, the measured amount of carbon is multiplied by 3.66; this explains the difference between 1.4 billion tons of carbon and 5.2 billion tons of CO₂ equivalent. The Atlantic Forest showed the highest soil carbon accumulation in both its natural vegetation and agricultural areas in the study. The Pantanal and the Caatinga (a semi-arid biome in the Northeast region) had the lowest carbon stock levels among the areas measured. The researchers considered the carbon present in the four soil layers typically analyzed in this type of study: 0 to 10 cm, 0 to 20 cm, 0 to 30 cm, and 0 to 100 cm.
In the topsoil layer, carbon stocks in areas of native Atlantic Forest vegetation were 86% higher than in the Caatinga and 36% higher than in the Cerrado (savanna-like biome). In agricultural areas, the Atlantic Forest surpassed the Pantanal and the Caatinga by 154% and 62%, respectively.
The large amount of data allowed the researchers to estimate the types of land conversion that remove the most carbon from the soil in each biome. They also determined how much the transition from monoculture to other agricultural practices can increase the carbon stored in the six biomes analyzed.
Converting native vegetation to monoculture results in a 33% loss of soil carbon in the Atlantic Forest and a 15.8% loss in the Cerrado. Conversely, converting a monoculture area to an integrated system in the Cerrado increases soil carbon by 15.3%.
In the Amazon, transitioning from monoculture to crop rotation or mixed cropping systems is estimated to generate a potential 14.1% increase in carbon.
"These are theoretical potentials that still require further study to determine their feasibility. However, we now have a foundation that offers promising prospects for application in new studies and even in public policy and the carbon credit market in Brazil, which is still in its infancy," Villela concludes.
In December 2025, Shell, Petrobras, and CCARBON launched Carbon Countdown, Brazil's largest carbon stock database. Using a standardized methodology, the project will collect and measure samples across the country to refine the results of the now-published study (read more at agencia.fapesp.br/57626 ).
The Research Center for Greenhouse Gas Innovation ( RCGI ), an Applied Research Center ( ARC ) based at USP and funded by FAPESP and Shell, supported the study as well.
The Foundation also supported the work through a Postdoctoral Fellowship for Júnior Melo Damian at Embrapa Agricultura Digital in Campinas.
About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.
