By Manuela Andreoni
Extensive regions of Brazil, a nation that contains over 10% of the world’s freshwater resources, are ablaze. This includes vast segments of the Amazon rainforest, the Pantanal wetlands—the largest in the world—as well as the Cerrado grasslands and the Atlantic forests along Brazil’s eastern shoreline.
The fire incidents in the country have surged more than twofold compared to the previous year, with an area equivalent to Costa Rica being consumed in August alone.
This month, smoke enveloped extensive sections of South America, darkening the skies of major urban centers such as Buenos Aires, Argentina; Sao Paulo; and La Paz, Bolivia. To add to the grim scenario, soot from the fires has resulted in black rain falling over several Brazilian cities.
Typically, fire season peaks around this time in Brazil, as farmers ignite pastures and incinerate freshly cleared deforested areas to eliminate unwanted plants. However, the destruction caused by fires has increased significantly this year.
Experts suggest that while many of these fires are likely ignited by human activity, the prevalence of dry vegetation has led to huge infernos that have spiraled out of control in alarming ways.
According to Brazil’s National Institute for Space Research, nearly half of the fires in the Amazon have engulfed untouched forests—an unusual occurrence. This indicates that measures to combat deforestation in the Amazon are no longer sufficient to prevent fires.
This illustrates that fire management strategies in some of the earth’s most biodiverse areas are ineffective. This poses a threat to countless life forms, including humans. The potential collapse of the Amazon rainforest could emit an amount of CO2 equivalent to 20 years’ worth of global carbon emissions.
Deforestation and fires
Deforestation remains a significant issue in South America. The Cerrado grasslands in eastern Brazil continue losing substantial tree cover as farmers cultivate soy crops that can span vast urban-like areas. Although deforestation in the Amazon rainforest has decreased, it is still occurring at a rate that surpasses the forest’s ability to recover.
Scientists assert that prioritizing the cessation of deforestation is critical. However, as the planet continues to warm, other emerging threats are becoming more prominent.
Research from 2018 indicated that during droughts in the Amazon, fire occurrences can rise even when deforestation rates drop. This is due to the dry vegetation from standing trees still providing fuel for the fires. “If fires are a direct consequence of deforestation, then a strategy targeting deforestation should effectively combat fires as well,” remarked Luiz Aragão, a scientist at the space research institute and one of the study’s authors. “Yet, we observe that it isn’t.”
Significant portions of South America are currently experiencing severe drought conditions, partly due to natural climate cycles like El Nino, which lead to reduced rainfall in the region. However, climate change is likely exacerbating the situation.
Last year, researchers determined that rising temperatures intensified the drought in the Amazon. It is also anticipated that weather patterns will shift soon as La Nina, which cools the Pacific and typically brings more precipitation to the region, begins.
Potential ecosystem alterations
Looking to the future, conditions are expected to deteriorate. Human activities continue to exhaust fossil fuels, warming the atmosphere, and scientists predict extreme droughts like the current one will become more common.
“Perhaps 2024 will be the least challenging of the upcoming years, as surprising as it seems,” stated Erika Berenguer, a senior research associate from the University of Oxford. “Climate models predict significant portions of the biome are set to become arid.”
Brazil’s environment minister, Marina Silva, recently informed senators that “we might witness the loss of the Pantanal by century’s end,” elaborating that reduced rainfall and rising temperatures present major challenges to the wetlands’ ability to recover to viable levels.
Should this trend persist, the transformation of the Amazon appears inevitable.
The forest has not adapted to burn like other ecosystems, such as boreal forests, Berenguer explained. The trees’ bark is thin, unlike that of redwoods and sequoias, meaning even a minor fire can prove lethal.
The Amazonian species that regenerate post-fire are not the grand trees emblematic of the rainforest but rather faster-growing, shorter plants that release far less carbon into the atmosphere through their trunks.
“Data indicates that even after 30 years post-fire, the affected forest still contains 25% less carbon than an untouched forest,” Berenguer concluded.
