Why is Brazil’s Pantanal breaking wildfire records? It has lost the most water since 1985, says study

The Pantanal, the world’s largest tropical wetland, has burned to the ground this year. This year’s fires set January-June records in the Pantanal, reported news agency AFP. And according to a recent study, there is a straightforward reason behind the spike in wildfires in the biome: It has lost the most water since 1985.

“The annual water surface (at least 6 months with water) in 2023 was 382,000 hectares - 61% below the historical average. There has been a reduction in the area flooded and the length of time the water remains. Last year, only 2.6% of the biome was covered by water. The Pantanal accounts for 2% of the country’s (Brazil) total water surface,” the study conducted by MapBiomas and released on June 26, said.

MapBiomas is an initiative of the Greenhouse Gas Emissions Estimation System (SEEG), which in turn has been developed by Brazilian civil society initiative the Climate Observatory. 

The last major flood in the Pantanal occurred in 2018. Last year was 50 per cent drier than 2018.

“In 2024, we didn’t have a flood peak. The year has seen a peak drought, which should last until September. The Pantanal in extreme drought is already facing fires that are difficult to control,” Eduardo Rosa, from MapBiomas, said in a note on its portal.

“There are over 10x as many fires in this global biodiversity hotspot this year so far relative to 2023, and with reports of unprecedented drying of the Paraguay River, fears of another record-breaking fire year are rising,” the non-profit Environmental Justice Foundation noted in a recent statement.

The Pantanal is home to some of the greatest biodiversity in South America, rivalling that of the Amazon, including caiman, the world’s largest rodent, the capybara, and the highest density of jaguars anywhere on Earth.

Other areas

The report also had sobering findings about the Amazon and other biomes.

The Amazon, north of the Pantanal, constitutes more than half of Brazil’s water surface. It had a water surface of almost 12 million hectares or 2.8 per cent of the biome’s surface last year, according to MapBiomas. This total represents a decrease of 3.3 million hectares compared to 2022, the organization said.

The Amazon suffered a severe drought last year, which Down To Earth had reported on.

“There has been isolation of populations and deaths of fish, dolphins and tucuxis,” said Carlos Souza Jr, coordinator of MapBiomas Água.

There was also bad news for the Pampa, the grasslands that cover a large area in southern Brazil, northern Argentina and Uruguay.

The water surface area of the Pampa’s reservoirs was 40 per cent lower than the average, according to MapBiomas.

However, there was good news from the Cerrado, a vast area of tropical savanna in eastern Brazil.

Last year, it had its largest water surface since 1985: 1.6 million hectares or nine per cent of the national total. This total is 11 per cent above the historical average for the biome.

According to MapBiomas, the gain in water surface area in the Cerrado occurred in anthropogenic areas, which increased by 363,000 hectares. Natural bodies of water, meanwhile, lost 696,000 hectares.

At the federal level, MapBiomas found that water covered 18.3 million hectares of Brazil, or two per cent of the national territory, in 2023. “Although this is twice the area of a country like Portugal, it represents a drop of 1.5% compared to the historical average. There was a loss of water in every month of 2023 compared to 2022, including the months of the rainy season,” the organization said.