Amazonian lakes are experiencing a rapid change, turning into seething puddles with temperatures exceeding those of hot tubs. This concerning movement is mainly responsible for extreme heat waves and stretched drought situations plaguing the place. Lake Tefé went through an unprecedented increase in temperature. In 2024, its shallow waters reached an astonishing 41°C, well above the usual temperature of a hot tub.
Our research reveals that Amazonian lakes are warming twice as fast on average as their rapidly warming surrounding Amazonian landscapes. Similarly, in the last three decades they have warmed 0.3 to 0.8°C per decade, exceeding the global average. Rising temperatures have recently seen one lake’s water temperature exceed 40°C (104°F). Meanwhile, excess clear skies and intense sunlight have led to evaporation drying out the lakes at unprecedented rates. Of the ten lakes studied, half measured incredibly hot daytime water temperatures over 37°C. This year, Lake Tefé typically got upwards of 30°C during the peak months. During 2024, it shot up to 40°C after losing about 3/4 of its surface area to extreme drought killing the world’s salt flats.
Unfortunately, even lake Badajós was not immune from the drought, shrinking by a staggering 90% over the same period. The consequences of these extreme conditions have been all too tragic. Floating carcasses of as many as 200 pink river dolphins began washing ashore on beaches during a six-week period starting in late September 2023. This type of mass die-off is unparalleled, with no similar events documented in the last 100 years.
Here’s my favorite tip from Adrian Barnett, senior lecturer in behavioral ecology at the University of Greenwich. For example, he explained that many aquatic species of fish, dolphins, and manatees all start to reproduce during low-water seasons. He sounded the alarm that 2023 would be a catastrophic year for reproductive success for these species.
“The paper shows the extraordinary impacts climate change is having, even on such huge ecosystems as the Amazon, and that these are not restricted to the forests, but the aquatic realm as well,” – Adrian Barnett.
Barnett underscored that although local solutions can go a long way in addressing the overheating of Amazonian lakes, the options are incredibly limited. He underscored the importance of looking at things more holistically. We need to get a handle on the causes of climate change, especially the emissions from fossil fuel usage.
“Something that’s happening at such a huge scale really requires a systems approach and that means attacking the root cause of the problem, which is fossil fuel emissions and the causes of global warming itself,” – Barnett.
The picture is bleak, with satellite images showing visible sandbanks on the Lake Tefé, a direct result from the extreme drought. Local resident Ayan Fleischmann described her frustration with the water’s extreme heat.
“We couldn’t even put our fingers in the water. It was really hot, not just in the top bit, but right down to the bottom,” – Ayan Fleischmann.