Glacial waters ‘carbon dioxide sinks’
Evidence suggests phenomenon isn’t just true for one spot
A new study by a former University of Alberta biologist has found that bodies of glacier-fed water in Northern Canada consume significant amounts of carbon dioxide from the atmosphere.
The research was conducted on Quttinirpaaq National Park on Ellesmere Island in Nunavut.
The team of scientists studied glacial rivers, along with the large lakes they feed into.
“What we found was that the rivers themselves were overwhelmingly carbon dioxide sinks. So they were consuming carbon dioxide from the atmosphere based on some very special properties of these rivers,” said Kyra St. Pierre, who completed the research for the study while at the U of A as a PHD student in 2015 and ’16.
One of those special properties, St. Pierre explains, is that glacial rivers, unlike temperate rivers, contain almost no life.
While there’s some microbial communities and bacteria in the river, the lack of biology means there’s very little production of carbon dioxide within the water itself.
The absence of life in these bodies of water, alongside a high prevalence of sediment, leads to a process called chemical weathering, which consumes carbon dioxide from the atmosphere. The result of the process is significant and wide-reaching, St. Pierre says.
“The finding also scales with the amount of meltwater that there is,” St. Pierre said. “The more meltwater there is, the more carbon dioxide is consumed. And this extends all the way — about 42 kilometres — into lakes downstream, which is pretty cool.”
While having large carbon sinks that reduce the amount of carbon dioxide in the atmosphere may sound like a good thing from a climate-change perspective, St. Pierre warns about the consequences of glacial melting and the impermanence of glacial bodies of water, especially at the world’s current rate of warming.
“An important consideration is that glaciers are a kind of finite resource,” she said.
“While they’re melting now, a glacier’s not going to be there forever if the climate keeps warming as it is. It’s something that’s a very short-term sink.”
The U of A is continuing work to find out how widespread this phenomenon is, including with research in the Jasper and Banff national parks. St. Pierre’s expectation is that this is an occurrence with glaciers around the world.
“We have at least some evidence that this isn’t true for just a single location,” St. Pierre said.
“It may not be true everywhere, but we’re trying to figure out what characteristics of the environment makes it so that this is kind of a dominant process.”