The Pat Kenny Show How lake temperatures surged past 40 °C in the Amazon Basin
Nov 12, 2025
Dr. Ruth Freeman, Director of Science for Society at Research Ireland, explores the alarming surge in lake temperatures exceeding 40 °C in the Amazon Basin and its devastating impact on wildlife. She reveals how rising temperatures deplete oxygen, stressing aquatic life. Additionally, Freeman discusses the legacy effect of microbes in soil, revealing how they help plants adapt to drought by 'remembering' past conditions. This fascinating interplay between climate extremes and microbial memory offers insights into both Amazonian and Irish ecosystems.
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Whole Lake Reached Lethal Temperatures
- Lake Tefe's entire water column reached about 41 °C during the 2023 Amazon heatwave, not just the surface.
- That extreme warming caused massive wildlife die-offs, including over 200 river dolphins in a short period.
Heat Cuts Oxygen And Raises Metabolic Stress
- Hotter water holds less oxygen, so warming both reduces oxygen and raises metabolic stress on aquatic animals.
- The combination of low oxygen and heat creates a 'double whammy' that drives fish and mammal die-offs.
Shallowness, Turbidity And Low Wind Amplified Heating
- In 2023 the lake lost water through evaporation and shrank about 75%, increasing turbidity and heat absorption.
- Reduced wind and darker, shallower water amplified heating, making the lake far more vulnerable to temperature spikes.