In a surprising twist that challenges popular climate solutions, scientists have discovered that planting trees in the Arctic and northern boreal regions could actually accelerate global warming rather than help combat it. In other words, researchers have a simple message: stop messing with the landscape of the Arctic, it’s making things worse.
The findings, published in Nature Geoscience, reveal that the dark surface of trees absorbs more heat than the reflective snow-covered ground they replace, potentially undermining well-intentioned climate mitigation efforts.
While tree-planting initiatives have gained momentum worldwide as a solution to climate change, this research suggests that location matters enormously. The study comes at a critical time, as various regions, including Alaska, Greenland, and Iceland, have begun implementing or considering large-scale tree-planting projects in their northern territories.
The problem lies in a phenomenon known as the albedo effect – the ability of surfaces to reflect sunlight back into space. The snow-covered ground in the Arctic reflects about 75% of incoming sunlight, while dark evergreen trees reflect only about 10%. This difference means that replacing open tundra with forests actually traps more heat in the Earth’s system, despite the trees’ ability to capture carbon dioxide from the atmosphere.
However, the issues don’t stop there. When trees are planted in Arctic regions, they disturb the soil, which in these areas serves as one of Earth’s largest carbon banks. The Arctic’s permanently frozen soils, or permafrost, contain more carbon than all the world’s plant life combined. When this soil is disturbed by tree planting and root growth, it releases stored carbon into the atmosphere, further contributing to global warming.
“Soils in the Arctic store more carbon than all vegetation on Earth,” explains lead author Jeppe Kristensen, an assistant professor from Aarhus University, in a media release. “These soils are vulnerable to disturbances, such as cultivation for forestry or agriculture, but also the penetration of tree roots. The semi-continuous daylight during the spring and early summer, when snow is still on the ground, also makes the energy balance in this region extremely sensitive to surface darkening, since green and brown trees will soak up more heat from the sun than white snow.”
The research team also found that trees in these regions face significant survival challenges. As climate change intensifies, these areas are experiencing more frequent wildfires, droughts, and pest outbreaks. When trees succumb to these disturbances, any carbon they’ve stored is released back into the atmosphere, negating their potential benefits as a carbon capture solution.
“This is a risky place to be a tree, particularly as part of a homogeneous plantation that is more vulnerable to such disturbances,” Kristensen continues. “The carbon stored in these trees risks fueling disturbances and getting released back to the atmosphere within a few decades.”
Source: https://studyfinds.org/stop-planting-trees-arctic-worse/