Why Arctic tundra is emitting more carbon?

Why in the NEWS?

• Arctic tundra is emitting more carbon than it absorbs, for first time in many millennia.

Key Points:

• In recent years, the Arctic tundra's ability to emit less and absorb more carbon has been impacted, according to the 'Arctic Report Card', an annual report on the polar region.
• The analysis, which incorporated more data and better methods of investigation, confirmed that the ecosystem has now become a source of carbon dioxide (CO2) and methane (CH4) emissions.
• That has happened for two main reasons:-
  • One is rising temperatures. The report said the Arctic is warming four times the global rate, and that annual surface air temperatures in the Arctic in 2024 were the second-warmest on record since 1900.
  • Another reason is that, in recent years, the Arctic has witnessed an increase in the frequency and intensity of wildfires. Last year was the worst wildfire season in the Arctic on record, and 2024 was the second-biggest year for wildfire emissions, according to the Vox (an American news and opinion website owned by Vox Media) report.
• According to a new report from the National Oceanic and Atmospheric Administration (NOAA), the Arctic tundra, a frozen treeless biome that has stored carbon for thousands of years, has now become a source of heat-trapping greenhouse gases (GHGs).
• These are the primary drivers of global warming.
• The main reasons behind the dramatic transformation of this Arctic ecosystem are increased forest fires and abnormally high temperatures.
• The Arctic tundra emitting more carbon than it stores will have global consequences as it will exacerbate climate change, the adverse effects of which are already being felt around the world.

How does the Arctic tundra store carbon?

• In a normal ecosystem, plants absorb carbon dioxide (CO2) from the atmosphere through photosynthesis.
• These plants grow, die, or are eaten by animals that grow and die.
• When they die, the carbon in their carcasses nourishes microorganisms like bacteria or fungi that break down large molecules and release carbon dioxide (CO2) back into the atmosphere, completing the carbon cycle.
• In the case of the Arctic tundra, the decomposition of organic matter slows dramatically due to the cold climate.
• Plant and animal remains can remain trapped in a layer of permafrost for thousands of years.
• Any ground that stays frozen for at least two years prevents carbon dioxide (CO2) from escaping back into the atmosphere.
• Scientists estimate that Arctic soils store more than 1.6 trillion metric tons of carbon across the region.
• That's nearly twice the amount of carbon in the atmosphere, according to a report by Vox.
  

What does the report say?

• The report says it's still possible to turn the Arctic tundra in the other direction, making it absorb more carbon than it emits.
• The only way to do that is to reduce global GHG (greenhouse gases) emissions.
• "With lower levels of climate change, you get lower levels of emissions from permafrost," Brendan Rogers, a scientist at the Woodwell Climate Research Centre who contributed to the Arctic Report Card, told NPR.
• New research from the Global Carbon Project science team published in November found that emissions from burning fossil fuels are likely to increase slightly in 2024 compared to last year.
• "With an estimated 4.2 billion tons of emissions from land-use change (such as deforestation), total CO2 emissions are projected to be 41.6 billion tons in 2024, up from 40.6 billion tons last year," the study says.