Thaw ponds studied in the Canadian Arctic were found to be an unaccounted sources of greenhouse gas emissions, contributing more to global warming than previously believed.
Most current climate models fail to take into consideration greenhouse gases emitted by thawing permafrost. A new study found that the methane emissions from such permafrost in the Canadian Arctic may be contributing more to global warming than previously believed. The findings emphasize on the need to take every minute factor into consideration before constructing such climate models in the future, stated a press release.
The biggest culprits of these huge amounts of greenhouse gases were found to be small thaw ponds in the region that abundantly emit methane. For the study, researchers from INRS'Eau Terre Environment Research Centre compared ponds of different shapes and sizes and studied their physiochemical properties and microbial technology. Using radiocarbon dating and new-generation molecular tools, they studied the sediment and examined the carbon transformation process.
"We discovered that although the small shallow ponds we studied represent only 44% of the water-covered surface in a Bylot Island valley, they generate 83% of its methane emissions," said water sciences doctoral student Karita Negandhi.
After analyzing the signatures of the methane emitted by these small ponds, researchers concluded that the greenhouse gases came from old carbon reserves that were buried deep within permafrost for centuries. As the permafrost thaws, organic matter becomes more abundant and promotes the production of aquatic microbes such as methanogenic Archaea, which use various sources of carbon, then release it into the atmosphere in the form of methane and carbon dioxide. Researchers noted that prolonged summers can lead to the increase of methane emission.
So why hasn't this large amount of greenhouse gas emission come to the notice of scientists before? This is primarily because these thaw ponds are located in isolated areas and have very less or no accessibility. However, studying these areas can help researchers get a clearer picture of the whole global warming process.
