WWF warns of tipping point risk as study reveals climate extremes accelerating in unexpected Amazon region

• Regions previously considered less at risk are now experiencing some of the sharpest increases in extreme heat and water stress, according to new research.  
• While the Southern Amazon remains the fastest-warming region overall, central northern Amazonia is emerging as a hotspot for accelerating extreme heat and moisture deficit, increasing the risk of drought, wildfire and ecosystem stress.  
• Scientists warn the findings could have implications for the resilience of the world's largest rainforest as drought and wildfire risks rise.  

Areas of the Amazon previously considered resilient to climate change may be under growing threat, a new study written in partnership with WWF UK reveals.  

Led by researchers at Lancaster University from an international team of more than 50 scientists, including leading experts from the Science Panel for the Amazon, the report challenges assumptions about climate risk and highlights the increasing risks facing the rainforest.  

The study raises concerns that increasing climate extremes could push the Amazon past a critical thresholds unless urgent measures such as prevention of fires, rapid reductions in global greenhouse gas emissions, prevention of further deforestation and degradation, and increased investment in climate adaptation are taken. 

 WWF has also partnered on the Global Tipping Points Report in 2025 which reported that impacts of climate change will lower the threshold at which widescale transformation of the rainforest to a degraded state could take place, and that just 20-25% deforestation could trigger this. To date, around 17% has already been lost.   

Widespread forest dieback and degradation would have global implications, releasing huge amounts of stored carbon, and changing regional climates. The immediate challenge within the Amazon is increased fire risk, with this year’s strong El Niño leaving the forest more exposed to drought. 

The findings strengthen the case for urgent action on fire prevention and tackling deforestation. In the longer term, mechanisms such as the Tropical Forest Forever Facility (TFFF), will help fund adaptation and conservation efforts in tropical forests facing rapidly intensifying climate extremes. This new research shows that the UK Government commitment to the TFFF announced last week (3 Sept) is timely, and now needs to be backed by measures to remove deforesting commodities from the UK’s supply chains.  

Mike Barrett, chief scientific adviser at WWF-UK, said:  "The rapidly increasing climate extremes revealed in this study highlight the urgent need for global action on climate change to protect vital ecosystems such as the Amazon. However, the new regions of risk also demonstrate the need to support other measures, including an end to deforestation and support for measures such as the Tropical Forest Forever Facility if we are to avoid critical tipping points and environmental collapse."  

The report's finding that climate extremes, in particular heat and moisture deficit, are much more severe than previously thought and that areas considered resilient to change are in fact at risk, raises the alarm on ecosystem collapse in the Amazon.  

With the El Niño of 2026 expected to be the strongest in living memory, and raising concerns over drought and wildfire risks, the study provides the most detailed assessment to date of how the climate has changed across the Amazon.  

Overall, the Southern Amazon remains the fastest-warming region. However Central Northern Amazonia is noted as emerging as a hotspot for accelerating extreme heat and moisture deficit, increasing the risk of drought, wildfire and ecosystem stress.  

Because the region contains extensive intact forest cover, natural savannas and considerable Indigenous territories, it was previously considered less at risk and the findings raise new concerns about the resilience of parts of the Amazon long thought to be among its strongest natural defences.  

The authors warn that continued increases in extreme heat and moisture stress could place growing pressure on vulnerable wildlife. In recent years there have been observed mass death of mammals, such as river dolphins during extreme weather, reductions in the size of bird populations, and changes to bird lifespans, appearance and behaviour  

Professor Jos Barlow of Lancaster University, the lead author of the report, said:

“We are most interested in things when they are at their hottest and driest as that is when the most harm can be caused by high temperatures. While this has been assessed in the Southern Amazon, which shares a largely similar dry season, it has never been assessed across the whole of the Amazon – which includes regions north of the equator which have a different dry season period.”

By dividing the Amazon into 11km grid cells and analysing high-resolution temperature and rainfall data from 1981 to 2023, researchers were able to identify how both average climate conditions and the most extreme hot and dry years have changed across the rainforest.  

While average temperatures across the basin have risen by around 0.21°C per decade for the last 40 years, researchers found that during the dry season 10% of the Amazon basin has experienced increases of extreme temperatures of at least 0.75°C per decade, equivalent to more than 3.2°C since 1981.  

“The rates of change in climate extremes are much higher than the rates of change of average climate in the Amazon, and the most affected regions are also different for extremes and average climate,” said Dr Nathália Carvalho, post-doctoral research associate at Lancaster Environment Centre. “This is important because we show that Amazonia’s climate is not changing uniformly. This information will be crucial when planning and implementing climate change adaptation strategies.

If climate extremes are accelerating in some of the Amazon's most intact forests, concern about wider ecosystem disruption increases both for nature and people.   

Professor Barlow said: “Extreme climate is a primary concern, contributing to forest fires, exceptional river levels, air pollution and high temperatures that can harm people as well as animals and the forest trees. The rates of change that we are seeing in the most affected regions are very alarming.

“Given the area that is experiencing the fastest growing in extreme temperature is far from the arc of deforestation, these rapid rises cannot be explained by local changes such as deforestation and land-use changes. It’s showing how the Amazon is being affected by global climate change. It’s the world’s emissions that are responsible.

Dr Joice Ferreira, at the Brazilian Agricultural Research Corporation (Embrapa) highlights the social concerns. “Extreme climate events are impacting local livelihoods in many ways, affecting key products like açaí. This removes the safety net that forests provide, threatening food security and weakening their role in a growing socio-bioeconomy. Most concerning, it could derail public policies currently being designed and implemented by Brazilian and state governments to drive positive transformation in the region, such as forest restoration plans. This scenario demands global action to halt climate change in the name of climate justice.”

To address these rapid changes in climate extremes, the authors argue that it is essential to halt and reverse deforestation and forest degradation in order to maintain a stable climate, protect the Amazon, safeguard biodiversity and secure the wellbeing of local communities.  

Professor Barlow added: “Adaptation measures are urgently required to address the impacts of these rapidly changing climate extremes, including preventing factors that amplify climate risks such as deforestation. We also need to bring in measures to support the fighting of forest fires as well as supporting local people when the rivers they rely on for navigation dry up, especially in a year like 2026 with the arrival of a super El Niño.” 

The study, ‘Rapid increase of climate extremes reveals new areas of concern in Amazonia’, has been published by Communications Earth & Environment.