European scientists have discovered the meltwater from glaciers in Kluane National Park emits methane – and more than they expected.
Scientists from University of Copenhagen in Denmark found elevated concentrations of methane in the samples from the meltwater around the Donjek, Dusty and Kluane glaciers. Methane is a greenhouse gas that is up to 28 times more potent at trapping heat than carbon, according to the United States Environmental Protection Agency.
The findings were published in the journal Arctic, Antarctic, and Alpine Research last December.
The research was led by Sarah Elise Sapper, a PhD fellow at the University of Copenhagen. Sapper travelled to Yukon in August 2022, and took a helicopter to visit glaciers selected by the research team.
No one had been to these glaciers to search for methane, Jesper Riis Christiansen, an associate professor at the University of Copenhagen who co-authored the study, told the News from Copenhagen. “So, it was basically a shot in the dark, it was a Hail Mary, let's just go and let's see what is there.”
However, upon arrival, Sapper could measure methane in the meltwater. At certain sites, there was so much methane in the meltwater it had de-gassed into the air.
The samples collected from the meltwater were sent to Denmark and Germany for further analysis. These samples showed methane concentrations were “45, 135, and 250 times higher in the meltwater of Dusty, Kluane, and Donjek glaciers” than if the meltwater had only been in contact with the atmospheric methane.
However, the source of this methane is not the meltwater itself, Christiansen said. The methane is produced below the glacier, dissolving into the meltwater and then moving to the edge of the glacier where scientists can measure it.
"So somewhere that is still totally unknown to us, somewhere under the ice, there's pockets or areas there where the methane is produced, and then it's coming into the meltwater, so that is why we have increased levels,” Christiansen said.
While the methane source isn’t determined, Christiansen said it’s probably biological in origin. If the methane is produced biologically, he said, it means there must be sources of organic carbon underneath the ice.
How that carbon gets under the glacier is a long story, stretching back potentially thousands of years. At that time, the area around the glaciers was probably warmer, and the glaciers were shrunken, Christiansen said. Plants and soil developed on the ground – both containing large amounts of organic carbon, he said.
But the climate cooled down, as has been shown to have happened in the northern hemisphere over the last couple of millennia (although that trend has been reversed and the northern hemisphere is now warming), said Christiansen. The glaciers grew, burying those sources of organic carbon underneath the ice, he said.
Organic carbon is one of three ingredients needed for methane production, along with water and a lack of oxygen, Christiansen said. There’s water underneath the ice, and lots of organic carbon from the buried plants and soil, but a lack of oxygen since it’s been blocked off by the ice and the water, he said.
“And this is what we're thinking is happening, that the carbon was buried under the ice once it moved back forward, and then we start producing methane.”
It was thought that this type of methane production would only be active underneath very large ice sheets with enough ice to prevent oxygen from getting beneath, said Christiansen. However, it’s interesting to have found this in relatively small glaciers, he said.
“It tells us that the environment below glaciers are maybe more similar, independent of its size,” he said. It’s interesting because little is known about extreme environments found underneath glaciers, which can't be studied directly.
“So finding methane there is a kind of an indicator that, okay, there's a kind of life system below these glaciers,” Christiansen said. “It's a basic understanding of life under very extreme conditions.”
Brian Lanoil, an associate professor in the Department of Biological Sciences at the University of Alberta, called the research “very interesting and exciting stuff.” Lanoil was not involved in the study.
Lanoil said micro-organisms live below Earth’s surface, including below permafrost and underneath glaciers.
“We don't really have a great understanding of how they survive there,” Lanoil said.
Understanding how these organisms live in these types of environments is important because it can tell us about life on other planets.
Moons in our solar system, revolving around planets like Jupiter and Saturn, have liquid water buried under kilometres of ice.
“And so, this is a similar kind of situation,” Lanoil said. “You have ice overlaying water. And if the micro-organisms in those systems and our glacier systems here on Earth can do this, we may be able to get insights into how organisms might be able to do that on other planets.”
Furthermore, it raises questions about how much methane glaciers contribute to the total amount in the atmosphere, Christiansen said, especially because methane is a stronger greenhouse gas than carbon dioxide.
“It might be significant. We just haven't really found it in the global signals yet.” Christiansen said.
Questions regarding the significance of glaciers to methane emissions may feel urgent, especially as glaciers around the world are melting due to climate change, as noted by the Intergovernmental Panel on Climate Change.
But the answers aren’t simple, Christiansen said. “It comes back to really how methane is released under the glacier, and that’s something we’re still trying to figure out, because the methane is not produced in the meltwater itself.”
Michel Baraër is a hydro-glaciologist at the École de technologie supérieure in Montreal. He was not involved in the study. He said while the study is interesting, the amount of sampling the researchers did only provides a snapshot of the methane production at the glaciers.
Baraër also said while concentrations of methane are higher than expected, swamps and lakes in more temperate regions create much more methane.
Jeffrey Crompton, a research scientist at the Geological Survey of Canada who was not involved in the study, told the News this data shows methane emerging from glaciers is not a unique phenomenon.
“So, it's not like there's a unique discovery here in the Yukon, but that methane released from glaciers could be actually pretty widespread.”
If glacial methane turns out to be widespread, Crompton said it will change the way that we can predict methane emissions. Melting permafrost is a known source of methane already, said Crompton.
“So, adding this piece of methane release from large glacier systems, I think could affect our predictions of future greenhouse gas or future warming from methane."
Contact Talar Stockton at talar.stockton@yukon-news.com