Last updated July 17, 2018 at 10:24 am
Study links microbiomes to greenhouse gases.
Frozen Lake Torneträsk, located next to the study site. Picture: Caitlin Singleton
We may soon have a clearer idea of how and by how much thawing permafrost will increase global warming over the next century.
An international team led by the University of Queensland has studied the microorganisms involved in permafrost carbon degradation and linked changing microbial communities and biogeochemistry to the rise of greenhouse gas emissions.
That’s a first and it’s significant given that, as PhD student Caitlin Singleton notes, permafrost stores around 50 per cent of the total global soil carbon (around 1580 billion tonnes).
As permafrost thaws, methane emissions increase, causing a positive feedback loop where increased atmospheric warming causes more thawing.
Researchers from the Australian Centre for Ecogenomics at UQ sequenced more than 200 samples from thawing and thawed permafrost sites in northern Sweden using techniques pioneered by Professor Gene Tyson.
They recovered DNA sequences of more than 1500 new microbial genomes involved in complex biochemical networks, and implicated a number in the production of greenhouse gases.
According to Singleton, northern permafrost wetlands contribute a significant portion of global methane emissions, particularly as collapsing permafrost can create the perfect anaerobic conditions for methane-producing microorganisms (methanogens) and their metabolic partners to thrive.
“This is important as methane is a potent greenhouse gas – 25 times more efficient at trapping the sun’s radiation in our atmosphere than carbon dioxide,” she said.
The paper is published in Nature.
