Climate scientist to study impact of extreme weather events on Amazon basin  

Dr Iestyn Woolway, from the School of Ocean Sciences, will be focusing on a critical and understudied scientific topic - how multiple extreme events, like heatwaves and droughts, can occur together and amplify their harmful effects.  

The research project, Extremes in Brazilian Amazon lakes and its implications for social-ecological systems, which is being supported by the Royal Society, aims to study these extreme events to better understand their impact and find ways to help the Amazon and its communities cope.  

The Amazon basin, in South America, is home to one of the world's largest and most important river systems, supporting a rich diversity of life and providing for millions of people.    

However, this region is increasingly experiencing extreme weather events, such as severe heatwaves, droughts, and floods. For example, in September 2023, the largest drought that ever occurred in the region led hundreds of lakes to collapse, including an unprecedented mortality of 209 dolphins in Lake Tefé, a large water system in the heart of the Amazon, due to extreme warming.  

These kinds of events are becoming more frequent and intense due to climate change, posing significant threats to the environment and the people living there.  

Dr Iestyn Woolway, who is a NERC Independent Research Fellow at Bangor University, said, “By combining historical data, satellite images, fieldwork, and computer models, we hope to gain a comprehensive understanding of these events and their impacts on both local communities and the environment.   

“We will work closely with Amazonian communities to identify the main challenges they face and develop practical solutions to increase their resilience to these extreme events.  

“The wider benefits of our research include providing valuable insights that can inform better policies and conservation strategies. By helping to protect the Amazon's unique ecosystems and supporting the livelihoods of its people, our project will contribute to the region's long-term economic stability and environmental health.  

“This research is vital for promoting sustainable development and ensuring the well-being of some of the world's most vulnerable communities.”  

Extreme temperatures can have severe consequences on the people living in the Amazon basin. These can be directly via heatstroke, dehydration, and worsening pre-existing health conditions. They can also be indirectly by impacting their livelihoods and the environment they depend on, such as proliferation of vector-borne diseases (illnesses that can be transmitted to humans by other living organisms such as mosquitoes and ticks).  

Hot lake water temperatures that often arise during a heatwave can have a dramatic influence on aquatic ecosystems, leading to thermal stress, a disruption of reproductive cycles, and increasing the susceptibility of species to diseases.  

In addition to this, extreme heat can exacerbate the effects of pollutants and reduce oxygen levels, leading to conditions that are detrimental to aquatic life. These changes can cascade through the food web, affecting not only fisheries but also the birds, mammals, and humans that depend on them, leading to food insecurity.   

Droughts, characterized by extreme low water levels, are another critical concern.   

The Amazon River's flow regime is highly seasonal, but the increasing severity and frequency of droughts are pushing the system beyond its natural variability. Low water levels can severely impact the river's navigability, hinder transportation, and reduce access to freshwater resources for drinking, sanitation, and agriculture.   

The compound nature of these events - where extreme hot air and water temperatures and droughts occur at the same time or right after each other - can amplify their individual impacts. For instance, hot and dry conditions can lead to the rapid evaporation of water bodies, intensifying water scarcity and increasing the stress on aquatic ecosystems.   

However, extreme events in the Amazon are typically studied in isolation. Understanding these compound events is crucial for developing effective management strategies and mitigation measures in the Amazon.