Thursday June 27, 2024
AGU —
Nearly half of the world’s large lakes have lost resilience, or the ability to bounce back after an abrupt disturbance, in recent decades, according to the first global assessment of long-term changes in lake resilience. Lakes in eastern North America and northern Europe have been hit the hardest, and dense populations and pollution are largely to blame, the study suggests. However, wealthier regions had healthier lakes, suggesting costly conservation efforts may pay off.
Both people and climate can gradually shift lakes away from their natural, healthy state. Warmer temperatures can increase evaporation, decreased precipitation can lower lake levels, and persistent pollution can chip away at the lake ecosystem’s health. When sudden disturbances hit, such as heat waves, droughts or floods, a “resilient” lake can recover; a vulnerable one may not be able to return to its previous state.
Assessing a lake’s resilience, which takes into account its structure and ecosystem functions, is crucial for scientists predicting how it will respond to climate- and human-induced changes. But long-term trends of changes in lake resilience at a global scale — and why they happen — remain unknown. The new study, published in Geophysical Research Letters, fills in this knowledge gap.