As Canada’s Arctic continues to accumulate plastic, and climate change takes its toll on northern environments and communities, experts have evidence to suggest each threat is exacerbating the other, according to a recent paper published in Nature this month.
As climate change affects temperatures and water patterns, says the review, plastic has become a more common sight within Arctic waters, snow, animals, and even ice drilled from some of the north’s most isolated glaciers. In return, these plastics contribute to an environment that absorbs more heat, encouraging changes in Earth’s climate that disproportionately impact the Arctic — which has warmed at a rate two to three times faster than the rest of the world in the past 50 years. However, given the limited amount of data available on the Arctic’s plastic build-up, experts say the intensity of the interplay between the two can’t be determined just yet.
Climate change’s role in the movement of plastic affects the Arctic in unique ways, said Dr. Jennifer Provencher, co-author of the paper, and a conservation biologist who studies the impacts of plastic on marine wildlife. As climate change increases surface-water temperatures, winds and water patterns shift, bringing plastics from farther south into even the most remote parts of the Arctic. This has caused microplastics — particularly those that have been evaporated into the atmosphere through the water cycle in other parts of the world — to be deposited into Arctic sea ice.
Dr. Provencher pointed to a study conducted in 2019, during which a team of American scientists drilled 18 ice cores from Lancaster Sound in Canada’s Arctic and found an abundance of plastic within them, indicating microplastic infiltration in some of the north’s most isolated areas. As elevated temperatures encourage the rapid melting of this ice, said Dr. Provencher, those with significant deposits will unleash a large amount of plastic into the Arctic.
“Currently, we have very little trend data on plastics accumulation, because we had almost no samples 10 years ago and nothing to build those trends from,” she said. “What I can say is that for most of the environmental samples that have been taken since, we find microplastics.”
Dr. Provencher and her co-authors reviewed a number of ways in which plastics have contributed to a similar uptick in the climate’s effects on the north, including how they could negatively impact key Arctic carbon sinks. Plastic particles’ impacts on the diets and habitats of phytoplankton communities could affect how much carbon these marine algae are able to absorb from the atmosphere. Microplastics also have the potential to darken sea ice and glacial snow, the paper said, interrupting their ability to reflect sunlight away from the Earth and help keep it cool.
This cooling system is integral to a stable Arctic environment, and its disturbance is a big reason why the far north is heating up so much faster than the rest of the planet, said Dr. Chris Derksen, a research scientist at Environment and Climate Change Canada who specializes in the cryosphere (the term for the frozen-water layer of the Earth’s surface). As rising temperatures melt snow and ice and leave behind heat-absorbent open sea water, the melting cycle is sped up, which disproportionately affects the Arctic.
“We call it a positive feedback loop, where a change in one direction reinforces and increases the severity of that change,” said Dr. Derksen. “So as we lose snow and sea ice because the planet is warming, that contributes to further warming, which causes us to lose more snow and sea ice ... and the cycle continues.”
The more plastic there is in the Arctic and around the world, the harsher the consequences are for the north — especially considering the chemical breakdown of plastics itself emits greenhouse gases. A study published in PLOS One in 2018 by Dr. Sarah-Jeanne Royer, an oceanographer at the Scripps Institute of Oceanography in San Diego, revealed that many of the plastics that make up the bulk of plastic pollution worldwide release methane and ethylene when degrading under sunlight — the former being 25 times more potent at trapping heat in the atmosphere than carbon dioxide.
“The direct consequences of the gases emitted from plastic solely in the Arctic might not be significant,” she said, “but if we are looking at the effect of plastics emissions on worldwide climate change, and consider how climate change affects the Arctic so much more than much of the world, then that is a problem.”
However, just how much plastic contributes to climate change — and vice versa — has yet to be measured. Experts are still in the process of quantifying just how much plastic there is in the Arctic, said Dr. Royer, in order to understand the true extent of the effects on Earth’s most vulnerable ecosystems.
Researchers include the intergovernmental Arctic Council, with whom Dr. Provencher has worked since 2020 on their Arctic Monitoring & Assessment Programme (AMAP). The international group aims to mitigate plastics and climate change in the Arctic through collaboration, and is the first project of its scale to tackle plastics in 11 “compartments,” or spheres, of the Arctic ecosystem — from air, to soil, to ice and snow, to animals. However, its status as a multi-country initiative leaves it at risk of interruption as the result of geopolitical conflict, including current council chair Russia’s recent aggression in Ukraine, which pushed the council to suspend all meetings until further notice last month.
“The good news is that there is a lot we can focus on at the domestic level,” she said. “What’s on pause is the international collaboration aspect of the work, but the international goals that we set are still there, and there’s no reason why we can’t work towards them.”
One such program is the Northern Contaminants Program (NCP), a funding program established in 1991 by the federal government to examine the risk that elevated levels of contaminants in wildlife species pose to northern Indigenous peoples’ traditional diets. Since then, NCP has funded a number of plastic-related projects, emphasizing community-based monitoring that uses the concerns of local populations as its baseline for research focus.
“It’s important that we co-develop the questions together [with Indigenous peoples],” said Dr. Provencher, “because in the end, it’s northern communities who feel the impacts of Arctic microplastic pollution the most.”
What is important for now is that approaches to mitigating plastic and climate change in the Arctic continue to account for one another, said Dr. Derksen, as neither threat exists in a vacuum.
“When we start to solve some of these problems, it’s not helpful to try and solve them in very carved-out, isolated areas,” he said. “But if we can understand the interconnected nature between them, then maybe it can spur us to try to solve them in a more comprehensive way, as opposed to just sort of throwing individual darts.”