More than 7000 lakes in Greenland, which were previously crystal clear, have turned brown over the past two years.
Researchers say ecologic change in the region has “pushed Arctic lakes across a tipping point” and they have started emitting carbon.
The change happened after record heat and rain in 2022 made changes in the lakes that would normally take hundreds of years. Around 7500 lakes are impacted.
University of Maine Climate Change Institute Associate Director Jasmine Saros released the findings in a paper published in the Proceedings of the National Academy of Sciences (PNAS).
“Greenland normally experiences snow in the fall, but the spike in temperatures (in 2022) caused the precipitation to fall as rain instead,” the study report said.
“The heat also caused permafrost – frozen soil that stores a significant amount of organic carbon – to thaw, releasing an abundance of carbon, iron, magnesium and other elements.
“As rain fell in record amounts, it washed these newly exposed metals and carbon from soil into lakes across Greenland’s western region, turning them brown.”
Professor said the magnitude and rate of change were unprecedented.
The researchers found a decrease in phytoplankton that absorbs carbon dioxide from the atmosphere through photosynthesis, and an increase in plankton that break downs and releases carbon.
Instead of sequestering carbon dioxide in the summer, the lakes became a source of it, with a 350 percent increase in greenhouse gas emissions from them.
The full report is on the University of Maine website.
