Known for its large flooded areas and rich biodiversity, the Pantanal faces a scenario of climate change and reduced water availability. Now, part of the biome has officially entered the list of areas susceptible to desertification in Brazil.
The change is included in the Brazilian Action Plan to Combat Desertification and Mitigate the Effects of Drought (PAB-Brazil 2025–2045), of the Ministry of Environment and Climate Change. The document classifies the cities of Corumbá and Ladário, in Mato Grosso do Sul, as municipalities with a dry sub-humid climate, a condition associated with greater susceptibility to desertification.
This does not mean that the Pantanal is turning into a desert. The classification considers the relationship between the amount of rain and the atmospheric water demand, indicating drier climate conditions.
The plan uses climate data from 1990 to 2020 and establishes national strategies to address land degradation and the effects of droughts by 2045.
Although the classification is recent, scientific research has already identified important changes in the behavior of rain and water in the Pantanal.
A study published in August 2025 analyzed the distribution of rainfall and drought episodes in the Brazilian Pantanal between 1994 and 2023.
Conducted by researchers from the State University of Mato Grosso (Unemat), the research identified a reduction in rainfall accumulation after the year 2000, especially between 2019 and 2023.
"Annual precipitation in the Pantanal varied between less than 1000 mm and more than 2500 mm, with higher amounts accumulated before the 2000s and a reduction after, especially in the last five years (2019-2023)", describe the authors.
To identify dry periods, researchers used the Standardized Precipitation Index (SPI), which allows the intensity and duration of below-average rain episodes to be assessed.
The results highlighted 2019, 2020, 2021 and 2023 among the years with the most severe droughts in the analysis of three-month periods.
"SPI-12 revealed alternating periods of drought and humidity in the last 30 years, with an increase in the frequency of dry events in recent years, indicating a decreasing trend", points out the study.
The northern and central regions of the Pantanal concentrated the most intense, severe and frequent episodes identified by the research.
Another study, published in 2025 in the journal Scientific Reports, investigated how climate and changes in land use have influenced the water dynamics of the Pantanal since the 1950s.
The research, led by Cassia B. Caballero, with the participation of Brazilian and foreign scientists, identified four major climatic periods: two wetter ones, between 1951 and 1964 and between 1976 and 2000, and two drier ones, between 1965 and 1975 and between 2001 and 2021.
According to the researchers, climate variability was responsible for 96% of the changes in water flow between the periods analyzed, while changes in land use and cover accounted for 4%, according to the model used.
"Climate variability was identified as the main driver (96%) of runoff and wetland dynamics," the authors state.
The survey also identified a reduction of approximately 30% in the extent of wetlands in the Pantanal between 1985 and 2021.
Although the biome has faced intense droughts in the past, the most recent period has seen higher temperatures and greater evaporative demand from the atmosphere, conditions that increase aridity.
The replacement of native vegetation with pastures and crops also changed the landscape of the Upper Paraguay Basin, responsible for supplying a large part of the floodable areas.
Scientists warn that warming and reduced rainfall could worsen the loss of wetlands, increase the risk of fires and compromise biodiversity.
"Climate change should amplify the impacts of the most recent dry period (2001–2021)", highlight the researchers.
The concern is especially important because the Pantanal depends on the natural cycle of floods and droughts to maintain its habitats and species diversity.
The inclusion of Corumbá and Ladário in the PAB-Brazil does not prove that desertification is already occurring in these municipalities. However, combined with scientific evidence of changes in rainfall and water dynamics, it reinforces the need for monitoring, conservation and adaptation measures to protect the largest system of tropical wetlands on the planet.
