Type: Prelims Only

Why in the News?

• The Arctic Tundra, a frozen treeless biome, has traditionally served as a carbon sink, storing vast amounts of carbon for thousands of years.
  • However, recent changes in this ecosystem are turning it into a source of greenhouse gases (GHGs), primarily carbon dioxide (CO2) and methane (CH4) according to National Oceanic and Atmospheric Administration (NOAA).

How does the Arctic Tundra store Carbon?

• The Arctic tundra stores carbon primarily through a process where plants absorb carbon dioxide (CO2) from the atmosphere via photosynthesis.
  • This carbon gets trapped in the soil and organic matter (plants and animals) that accumulate over time.
• The cold Arctic climate slows the decomposition of plant and animal remains, meaning that organic materials, including carbon, remain locked in the permafrost.
  • This permafrost acts as a natural storage system, preventing CO2 from being released back into the atmosphere.
• Scientists estimate that the Arctic tundra holds about 1.6 trillion metric tonnes of carbon, which is roughly double the amount of carbon in the Earth’s atmosphere.

Why is the Arctic Tundra emitting more carbon than absorbing it?

• Rising temperatures in the Arctic are causing the permafrost to thaw at an accelerated rate.
  • When permafrost thaws, microbes in the soil become active, breaking down the organic material trapped in the frozen ground, which results in the release of carbon dioxide (CO2) and methane (CH4), two potent greenhouse gases.
  • The Arctic has been warming at a rate four times faster than the global average.
  • 2024 was the second-warmest year on record for the region, contributing significantly to the thawing of the permafrost.
• Wildfires in the Arctic have become more frequent and intense, further accelerating the thawing of permafrost. Wildfire smoke also contributes to the release of greenhouse gases.
• Between 2001 and 2020, the combination of rising temperatures and increased wildfires led to the Arctic tundra releasing more carbon than it absorbed, marking a significant shift in its role from a carbon sink to a carbon emitter.

Why in the News?

A recent study suggests that the Arctic Ocean may experience its first ice-free day—where sea ice falls below one million square kilometres—by 2030, or even sooner.

Key Highlights of the Study

• First Ice-Free Day Prediction: The study predicts that the Arctic Ocean could experience its first ice-free day (less than one million square kilometres of sea ice) by 2030, or even sooner, depending on climatic conditions.
• Simulations and Models:
  • 11 different climate models were used to run 366 simulations from 2023 to 2100 to assess the future of Arctic sea ice.
  • Most simulations predict the ice-free day within 7 to 20 years, with some models suggesting it could happen as early as September 2027.
• Conditions for Ice-Free Day: The occurrence of an ice-free day will depend on a combination of unusually warm seasons and stormy weather, which accelerates the melting of the sea ice.
• Impact on Sea Ice: Once the first ice-free day occurs, it could be followed by an ice-free period lasting between 11 to 53 days, potentially leading to the first ice-free month.

How does the Arctic Tundra store Carbon?

• The Arctic tundra stores carbon primarily through a process where plants absorb carbon dioxide (CO2) from the atmosphere via photosynthesis.
  • This carbon gets trapped in the soil and organic matter (plants and animals) that accumulate over time.
• The cold Arctic climate slows the decomposition of plant and animal remains, meaning that organic materials, including carbon, remain locked in the permafrost.
  • This permafrost acts as a natural storage system, preventing CO2 from being released back into the atmosphere.
• Scientists estimate that the Arctic tundra holds about 1.6 trillion metric tonnes of carbon, which is roughly double the amount of carbon in the Earth’s atmosphere.

Why is the Arctic Tundra emitting more carbon than absorbing it?

• Rising temperatures in the Arctic are causing the permafrost to thaw at an accelerated rate.
  • When permafrost thaws, microbes in the soil become active, breaking down the organic material trapped in the frozen ground, which results in the release of carbon dioxide (CO2) and methane (CH4), two potent greenhouse gases.
  • The Arctic has been warming at a rate four times faster than the global average.
  • 2024 was the second-warmest year on record for the region, contributing significantly to the thawing of the permafrost.
• Wildfires in the Arctic have become more frequent and intense, further accelerating the thawing of permafrost. Wildfire smoke also contributes to the release of greenhouse gases.
• Between 2001 and 2020, the combination of rising temperatures and increased wildfires led to the Arctic tundra releasing more carbon than it absorbed, marking a significant shift in its role from a carbon sink to a carbon emitter.

Why does it matter?

• Climate Change Acceleration: The loss of sea ice will amplify the Albedo effect, causing the Arctic region to absorb more sunlight and heat, which will accelerate global warming and trigger extreme weather events in mid-latitudes.
• Rising Sea Levels: The loss of Arctic ice contributes to sea level rise, with potential long-term impacts on coastal populations and ecosystems, particularly if the Greenland ice sheet melts completely, which could raise sea levels by 6 meters.
• Ecosystem and Species Impact: The melting of sea ice will threaten species that rely on the ice for habitat, such as polar bears, walruses, and reindeer, disrupting the Arctic food chain.
• Human and Infrastructure Threats: Arctic communities and their infrastructure are at risk as the region warms at four times the global average, threatening the livelihoods of people living in these areas.