Greenland's lakes face carbon crisis after warm weather shift
Atmospheric rivers have significantly changed Greenland's ecosystem. Lakes, once renowned for their clear, blue waters, have now transformed into brown water reservoirs. In a recent study, scientists discovered that instead of absorbing carbon dioxide, these lakes are beginning to emit it.
Scientists from the University of Maine report that approximately 7,500 lakes in the western part of Greenland underwent significant changes after an exceptionally warm and rainy autumn of 2022. The high temperatures and rainfall, which occurred instead of snow, thawed permafrost, releasing substantial amounts of carbon, iron, and magnesium into the environment.
The rainfall allowed elements to enter the lakes, altering their chemical composition. The increase in organic matter promoted bacterial growth, resulting in the browning of waters and the emergence of an unpleasant odour. These changes threaten local communities that depend on the lakes as a drinking water source.
Alterations in the water's chemical composition affect the biodiversity of plankton. Darker waters block sunlight, leading to a decrease in the number of phytoplankton, which absorbed carbon dioxide. Consequently, CO2 emissions from the lakes have increased by 350%.
Atmospheric rivers as a catalyst
Atmospheric rivers are relatively narrow bands where increased humidity occurs. These formations in the atmosphere are responsible for transporting vast amounts of water vapour. This vapour usually originates from the tropics or high-humidity areas, most often absorbed from the surface of warm oceans. This phenomenon may have been the source of intense rainfall in Greenland, consequently triggering a chain reaction that has destabilised freshwater ecosystems in the region.
Uncertain future of lakes
Scientists must now observe the long-term consequences of these changes. It remains unknown whether the lakes will return to their original state and how quickly this might occur. Atmospheric phenomena, local ecosystems, and the global climate clearly interact with one another.
The coming years will reveal whether the lakes of Western Greenland can withstand the influence of atmospheric rivers or if they will undergo permanent changes. These observations will be crucial for understanding ecosystems' ability to self-regulate in the face of rapid climate changes.
