Permafrost studies may be severely underestimating the methane released in the Arctic in the course of a year, according to a paper published in late December in the Proceedings of the National Academy of Sciences.
Methane is a shorter-lived greenhouse gas than carbon dioxide, but it is 25 times more potent by weight.
Past research has only collected data for the summer months, when the Arctic is at its warmest. But “the cold period in general is the time of the year that is warming the fastest in these Arctic ecosystems,” said lead author Donatella Zona of San Diego State University and the University of Sheffield. “Really, if we’re thinking about the future of climate change, we need to understand if this time of the year is important.”
Permafrost models “are important because they allow scientists to make projections about how severe global warming will be in the future and help policy-makers make decisions about how much—and how quickly—global carbon emissions need to be reduced,” the Post explains. So between June 2013 and January 2015, “Zona, along with a group of nearly 20 other scientists, decided to investigate whether cold-season methane emissions were really as negligible as the models have assumed.”
Their results show that “cold-season methane emissions are not only not negligible—they’re pretty significant,” Harvey writes. While emissions varied somewhat from one site to the next, “emissions from September to May accounted for about half of all the methane emitted from those sites throughout the entire year.”