What is Arctic Boreal Zone (ABZ)?

 Why in news ? The Arctic Boreal Zone, encompassing treeless tundra, boreal forests, and wetlands spread over 26 million square kilometres, has undergone a significant transformation. New research has revealed that 40 per cent of this region has become a carbon source, releasing more carbon dioxide into the atmosphere than it absorbs, marking a shift from its role as a carbon sink for millennia.

A carbon sink absorbs more carbon from the atmosphere than it releases. A carbon source, on the other hand, releases more carbon than it absorbs.

• “The Arctic boreal region is known for being soil organic carbon reservoirs. There is this concern that part of the soil stock will be released as carbon dioxide,” Anna Virkkala, a research scientist at the Permafrost Pathways initiative at Woodwell Climate and lead author of the study, told Down To Earth.
• The study, published in the journal Nature Climate Change, attributed this transition to longer growing seasons, increased microbial activity and an uptick in the frequency and intensity of wildfires. The researchers suggest the shift may have started before 1990.

• The findings align with NOAA’s 2024 Arctic Report Card, which also highlighted that the Arctic tundra, a treeless region, is becoming a net carbon source, largely due to warming temperatures and escalating wildfire activity in the Northern polar region..

“Our observations now show that the Arctic tundra, which is experiencing warming and increased wildfire, is now emitting more carbon than it stores, which will worsen climate change impacts,”  NOAA Administrator Rick Spinrad, said in a statement. “This is yet one more sign, predicted by scientists, of the consequences of inadequately reducing fossil fuel pollution.”

The study gathered data from 200 monitoring sites between 1990 and 2020, analysing year-round changes in carbon dynamics alongside shifts in climate and fire patterns. While the region acted as a terrestrial carbon dioxide sink during the 2001–2020 period, more than 30 per cent of it was a net carbon dioxide source. Factoring in fire emissions increased this figure to 40 per cent.

About Arctic Boreal Zone (ABZ):

The Arctic Boreal Zone (ABZ) is a critical ecological region located in the high-latitude Northern Hemisphere, encompassing parts of the Arctic and boreal (sub-Arctic) regions. This zone spans across several countries, including Canada, Russia, the United States (Alaska), the Nordic countries, and Greenland. The ABZ is characterized by its unique climate, ecosystems, and significance in global environmental systems. Below is an overview of key aspects of the Arctic Boreal Zone:

1. Geographical Extent:

• The ABZ covers areas with boreal forests (taiga) and tundra ecosystems, transitioning from forested regions to treeless Arctic tundra.
• It includes vast expanses of coniferous forests, wetlands, peatlands, permafrost regions, and river systems.

2. Climate:

• The climate is cold and subarctic, with long, harsh winters and short, mild summers.
• The zone is highly influenced by climate change, experiencing faster warming rates compared to other regions on Earth due to the Arctic amplification effect.

3. Ecosystems:

• The boreal forests (taiga) are dominated by coniferous trees such as spruce, fir, pine, and larch.
• The tundra is characterized by low-lying vegetation, including mosses, lichens, shrubs, and grasses.
• This zone is home to diverse wildlife, including caribou, moose, wolves, bears, and migratory birds.

4. Significance:

• Carbon Storage: Boreal forests and peatlands act as significant carbon sinks, storing vast amounts of organic carbon in the form of vegetation and soil.
• Climate Regulation: The ABZ plays a crucial role in regulating the Earth’s climate through its impact on carbon and energy cycles.
• Biodiversity: It supports unique flora and fauna adapted to extreme conditions.
• Indigenous Communities: Many Indigenous peoples depend on the natural resources of the ABZ for their livelihoods and cultural practices.

5. Environmental Challenges:

• Climate Change: Rising temperatures are leading to permafrost thaw, altering ecosystems, releasing stored greenhouse gases, and disrupting habitats.
• Deforestation and Exploitation: Logging, mining, and oil extraction pose significant threats to boreal forests.
• Wildfires: Increasingly frequent and intense wildfires, driven by warmer temperatures, are damaging forests and releasing carbon into the atmosphere.
• Biodiversity Loss: Habitat changes threaten species survival, especially those adapted to cold climates.

6. Global Importance:

• The ABZ serves as a global climate indicator, reflecting the broader impacts of human activity and climate change.
• It contributes to the global water cycle through its vast river systems that feed into the Arctic Ocean.
• The zone is pivotal for understanding feedback mechanisms related to permafrost, snow cover, and ice dynamics.

7. Conservation Efforts:

• International cooperation through agreements such as the Arctic Council focuses on sustainable development and environmental protection in Arctic and boreal regions.
• Scientific research and monitoring programs aim to better understand the ABZ’s role in global systems and address challenges posed by climate change.