September 28, 2026: New climate research is raising fresh concerns about the long-term stability of the Amazon rainforest, as rising temperatures, increasing water stress and forest fires combine to put pressure on one of the world’s most important ecosystems.

A new study highlighted by NOAA Climate.gov suggests that up to 40% of Amazon forests could begin shifting toward savanna-like ecosystems before the middle of this century under high greenhouse-gas emission scenarios. The research accounts for the combined effects of fire, water stress and competition among plants, providing a more detailed assessment of the risks facing the rainforest.

Fire and Drought Create Combined Pressure

The Amazon depends heavily on a stable cycle of rainfall and moisture recycling. Increasing drought can weaken trees, reduce their ability to recover from disturbances and create conditions that are more favourable for wildfires.

Recent monitoring by the Amazon Cooperation Treaty Organization found that dry conditions expanded across the Amazon Basin in August 2026. The number of detected hotspots increased sharply from 2,757 in July to 12,123 in August, while average rainfall declined from about 90 mm to 55 mm. Average temperatures were also around 1.36°C above the climatological average.

Northern Amazon Also Showing Rapid Changes

Research published in September found that parts of the central-northern Amazon, previously considered comparatively resilient, are experiencing rapidly increasing climate extremes.

Researchers reported that roughly 10% of the Amazon Basin has experienced increases in dry-season extreme temperatures of at least 0.75°C per decade, with temperatures in those areas rising by more than 3.22°C since 1981. The researchers said increasing heat and water stress could raise risks from drought, wildfire and ecosystem degradation.

Deforestation Can Increase the Risk

Climate change is not the only factor affecting the rainforest. Deforestation can disrupt the movement and recycling of moisture across the Amazon, potentially making some areas drier and reducing the forest’s resilience.

A Nature study published in 2026 found that the combination of global warming and deforestation could substantially lower the climate threshold at which large portions of the Amazon forest become unstable. The study modelled different emissions and land-use scenarios and found that the risks increase considerably when warming is combined with substantial forest loss.

Scientists stress that these are modelled scenarios rather than predictions that the entire Amazon will suddenly disappear. The timing and geographical extent of future changes depend on greenhouse-gas emissions, deforestation, fires, rainfall patterns and the ability of ecosystems to adapt.

Why the Amazon Matters Globally

The Amazon plays a major role in the global climate system. Its forests store enormous quantities of carbon and help regulate regional rainfall through the movement of water between vegetation and the atmosphere.

Large-scale forest degradation could therefore have consequences extending beyond the Amazon region, affecting biodiversity, agriculture, water availability and carbon storage.

The latest research indicates that protecting existing forests, limiting deforestation and reducing greenhouse-gas emissions are important factors in reducing the risks identified by climate models.