Marie Bulínová, a Ph.D. candidate in the Geosciences Department at UiT The Arctic University of Norway, is focusing the torch beam of her important research career on this question. Her work highlights that Arctic lakes are major contributors to methane emissions globally. If climate change continues to raise global temperatures, these lakes will produce considerably more methane than expected. Yet her research uncovers a critical lack of understanding about how these ecosystems will react under a warming climate. Together with that international team, she spent three years conducting this cutting-edge research.
The team of researchers took their coring efforts on lake sediment coring to Aspevatnet in Lyngen, Norway. Arctic lakes are one of the most abundant natural methane sources. Despite this, researchers remain unable to fully grasp the processes that govern the production of methane and the release from lake sediments. This study seeks to address that knowledge gap and help inform more expansive climate modeling efforts.
Investigating Arctic Lake Ecosystems
Bulínová and her collaborators led an extensive field study to ten Arctic lakes throughout Svalbard and subarctic Scandinavia. In 2021 and 2022, they traveled to many of these lakes several times, in both summer and winter. More importantly, their work showed that unique features of each lake determine methane emission potential the most.
“One of the striking aspects of this work is how different Arctic lakes are from each other. Some release much more methane than others, depending on local factors like vegetation cover, lake shape, or sediment composition. That’s why it’s essential to study a wide range of lake types if we want to understand the Arctic’s role in future climate feedbacks.” – Marie Bulínová
The researchers found that the majority of the methane was produced in the first 10 centimeters of lake sediment. What they found left scholars reeling. They established an unambiguous relationship between ecosystem productivity and methane emissions, which only muddies the waters on climate change effects in these complex ecosystems.
“We were surprised by how clearly the productivity of the ecosystem was linked to methane production.” – Marie
Implications for Climate Change
The study’s implications are widespread, especially as growing seasons lengthen and Arctic landscapes become more verdant. Backgrounder Arctic Lakes Warmer, wetter conditions increase biological productivity in Arctic lakes, according to new research. Consequently, these alterations result in heightened methane emissions from the sediments themselves.
“Our results show that warmer and wetter conditions increase biological productivity in Arctic lakes, which in turn drives methane emissions from their sediments.” – Marie
Findings underscore the need to integrate lake sediments into greenhouse gas budgets across the Arctic region. Methane is over 25 times more potent than carbon dioxide as a greenhouse gas, making its release a critical factor in climate change discussions.
Understanding Feedback Loops
Scientists are still in the process of peeling back the layers of Arctic ecosystems. As Bulínová says, it’s critical to know all the feedback loops in action. With the speed and scale at which these changes are taking place, the Arctic poses interesting questions regarding what these changes might mean for the global climate system.
“The Arctic is changing rapidly, and we need to understand all the feedback involved.” – Marie
She cautions that increases in ecosystem productivity – often considered a net positive – could inadvertently increase methane emissions from those ecosystems. This would ironically accelerate global warming even more.
“Our work suggests that increases in ecosystem productivity—something we could think of being positive—can also increase methane release and further accelerate warming.” – Marie
