The effects of climate change in the Amazon are becoming less gradual and uniform, and climate extremes have also been affecting better-preserved areas of the forest, according to the article“Rapid increase of climate extremes reveals new areas of concern in Amazonia,” published in the journal *Communications Earth & Environment* with contributions from researchers at IPAM (Amazon Environmental Research Institute).
According to the study, the southern portion of the biome, known as the “arc of deforestation,” accounts for the greatest loss of native vegetation and has experienced the fastest warming. But it was in the north-central region of the forest—which has the greatest forest cover—that the climate was most extreme. For the researchers, this shift reinforces the argument that the global context of the climate crisis has impacted even the best-preserved areas of the forest, far from the epicenter of deforestation in Brazil.
“This discrepancy between the area with the highest deforestation—the primary local driver of climate change—and the areas most affected by climate extremes demonstrates that major greenhouse gas-emitting countries bear an increasingly greater responsibility for the social and ecological imbalance in the Amazon. This reinforces not only the importance of reducing global emissions for the forest’s balance, but also that nations outside the Amazon bear responsibility for its instability and should therefore pay for its recovery,” the scientists write.
The study brought together researchers from 31 institutions in six countries, with participation from leading centers and universities in environmental research, such as the University of Oxford, Yale University, Columbia University, Lancaster University, Wageningen University, and NASA. In Brazil, in addition to IPAM, participating institutions included INPE (National Institute for Space Research), INPA (National Institute for Amazonian Research), EMBRAPA (Brazilian Agricultural Research Corporation), and the Emílio Goeldi Museum of Pará (MPEG), as well as federal and state universities from different regions of the country.
A New Way to Measure Climate
To arrive at these results, the researchers analyzed temperature and drought peaks in each region of the Amazon, comparing the results to the average recorded across the entire biome. This made it possible to pinpoint where and when the most critical climate phenomena occurred, as well as to determine how far the measurements from each area deviated from the biome’s average records.
“The most concerning finding is that the wettest and best-preserved region of the Amazon is already experiencing extremes of heat and drought. These forests evolved under very humid conditions and are particularly sensitive to water shortages. As they become hotter and drier, they lose some of their natural resistance to fire. This shows that keeping the forest standing is essential, but it is not enough: without reducing global emissions, even the most well-preserved areas of the Amazon will be increasingly exposed to climate extremes and the risk of fires,” explained Ane Alencar, director of science at IPAM.
Scientists found that while the southern portion of the biome recorded a significant increase in temperature and rainfall variability, these values were in line with the global average rise in temperatures. The central region of the forest, in turn, experienced variations 2.34 times greater than the biome’s average.
According to the researchers, this variation is due to the region having experienced more exceptionally hot and dry periods, during which biodiversity loss is more rapid than in regions that have warmed gradually.
“The rates of change in extreme weather events are much higher than the rates of change in average climate in the Amazon, and the regions most affected also differ between extremes and average climate. This is important because we have shown that the Amazon’s climate is not changing uniformly. This information will be crucial for planning and implementing strategies to adapt to climate change,” says Nathália Carvalho, co-author of the study and a postdoctoral researcher at the Lancaster Environment Centre.
Extreme Weather and Water Stress
Extreme weather events cause the most damaging effects associated with climate change. Disproportionately hot summers are responsible for increased mortality among people, animals, and plants, as well as severe damage to forest ecosystems. In the Amazon, extreme events—such as those recorded in 2023 and 2024 and expected during the current El Niño—are associated with large-scale wildfires, species extinction, and impacts on human health and air quality.
“We are most interested in the phenomena that occur when climatic conditions are hotter and drier, as it is during this period that high temperatures can cause the most damage,” said Professor Jos Barlow of Lancaster University, one of the study’s authors. “Although this has already been assessed in the southern Amazon, which has a very similar dry season, it has never been assessed across the entire Amazon, which includes regions north of the Equator with a different dry season.”
The study demonstrates that climate change in the Amazon is neither gradual nor uniform and highlights the enormous challenge facing public policy makers in the face of rapidly rising extreme temperatures and water shortages. These phenomena also warrant attention because they are occurring in the north-central Amazon, far from the deforestation arc.
