How Deforestation and Climate Change Are Drying Out the Amazon
A new study untangles the intertwined forces reshaping the world’s largest rainforest.
Breaking the Ice:
A new study has put hard numbers to a question that has long puzzled scientists: how much of the Amazon’s transformation is due to global climate change, and how much is caused by deforestation on the ground? Analyzing 35 years of satellite and atmospheric data across 29 regions of the Brazilian Amazon, the researchers disentangled the relative impacts of land clearing and global warming.
While rising greenhouse gases like CO₂ and methane are almost entirely driven by global emissions, regional deforestation is a leading culprit in reshaping rainfall and temperature patterns. Specifically, the team found that deforestation accounted for nearly three-quarters of the decline in dry-season rainfall and about one-sixth of the region’s rising temperatures since 1985. This dual stress—climate change from afar, land clearing up close—has destabilized the Amazon’s delicate hydrological and carbon cycles.
Quick Melt:
The Amazon rainforest regulates not only regional weather but also plays a critical role in the Earth’s climate system, storing hundreds of billions of tons of carbon. When the forest is intact, it acts as a carbon sink. But deforestation, coupled with warming and prolonged dry seasons, is nudging parts of the Amazon toward becoming a net carbon source.
The study shows that deforestation exerts its most dramatic influence early on—within the first 10–40% of forest loss—suggesting that even relatively small cuts can produce outsized disruptions. Longer, hotter dry seasons heighten fire risk, reduce evapotranspiration (the moisture trees release into the air), and create feedback loops that reinforce drying and heating.
Looking ahead, the authors project that if deforestation continues at recent rates, by 2035 the Amazon could see an additional 0.6°C temperature rise and a further 7 mm drop in dry-season rainfall. This could push parts of the biome toward climates resembling the drier Cerrado savanna—or worse, the semi-arid Caatinga.
The Thaw:
How Do Forests and Climate Interact? AccumulationZone Explains.
The Amazon is like a massive air conditioner and water tower rolled into one. As we strip away the forest and warm the planet, we’re breaking both machines at once. The risk is not just a local ecological tragedy, but a global climate destabilizer.
Through evapotranspiration, trees pump moisture into the atmosphere, which cools the air and fuels rainfall. Cut the trees, and you sever these pumps. Less moisture means fewer clouds, less rain, and hotter ground temperatures.
Meanwhile, greenhouse gases accumulate in the atmosphere, trapping heat globally. The Amazon feels this double bind acutely: deforestation amplifies local heating and drying, while climate change steadily raises the background temperature. The study highlights that these processes are not simply additive—they interact nonlinearly, making the forest more vulnerable than previously recognized.
This interplay between local land use and global climate is a textbook example of feedbacks in Earth systems science. The forest shapes the climate, but the climate also shapes the forest. Cross a certain threshold, and the system can flip into a new state—one with less rainfall, higher fire risk, and diminished biodiversity.
Final Thoughts
The Amazon has long been called the “lungs of the planet,” but this study suggests a more precise metaphor: it is both a thermostat and a reservoir. Its stability hinges on keeping deforestation and emissions in check. Allowing either to spiral threatens not only the rainforest itself but also the climatic balance that sustains life across continents.