Arctic tundra, a frozen treeless biome that has stored carbon for thousands of years, is now a source of heat-trapping greenhouse gases (GHGs) that are the primary driver of global warming, according to a new report from the National Oceanic and Atmospheric Administration. Administration (NOAA). Increased forest fires and unusually high temperatures are the main reasons behind the dramatic transformation of this arctic ecosystem.
The analysis, the ‘Arctic Report Card’, is an annual report on the polar region and was published last week.
If the Arctic tundra emits more carbon than it stores, it will have global consequences because it will exacerbate climate change, the adverse effects of which are occurring around the world.
How does the arctic tundra store carbon?
In a typical 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 corpses feeds microbes like bacteria or fungi that break down the larger molecules and release CO2 back into the atmosphere, thus completing the carbon cycle.
However, in the case of arctic tundra, the decomposition of organic matter slows dramatically due to the cold climate. Plant and animal remains can remain trapped in layers of permafrost for thousands of years – any ground frozen straight for at least two years – preventing CO2 from returning to the atmosphere. Scientists estimate that Arctic soils store more than 1.6 trillion metric tons of carbon in the region. This is almost double the amount of carbon in the atmosphere, according to a report Vox.
Why is the arctic tundra emitting more carbon than it absorbs?
In recent years, however, the arctic tundra’s ability to emit less and absorb more carbon has taken a hit. The new analysis, which included more data and better methods of examination, confirmed that the ecosystem is now a resource. CO2 and methane (CH4) – More powerful GHG-emissions.
This is due to two main reasons. One is that the temperature is increasing. The report notes that the Arctic is warming at four times the global rate, and that the Arctic’s annual surface air temperature in 2024 will be the second warmest on record since 1900.
As a result, the Arctic’s permafrost is melting, which means that soil microbes are becoming active and breaking down organic matter, releasing CO2 and CH4 into the atmosphere.
Speaking to NPR, Twila Moon, editor-in-chief of the Arctic Report Card and a scientist at the National Snow and Ice Data Center, said permafrost is like a chicken in the freezer — as long as it’s frozen, microbes stay away.
“Once you take that chicken out of your freezer, it thaws and all those microbes go to work, breaking down the chicken, rotting it,” she said. “Permafrost is really doing the same thing.”
Another reason is that the Arctic has seen an increase in the frequency and intensity of wildfires in recent years. Last year was the worst wildfire season in the Arctic, and 2024 was the second-biggest year for wildfire emissions, according to a Vox report. Wildfire smoke adds GHG emissions to the atmosphere and also accelerates the melting of permafrost.
Between 2001 and 2020, forest fires and rising temperatures caused Arctic tundra to emit more carbon than its plants removed from the air, possibly for the first time in several millennia, the report said.
What happens now?
The analysis suggests it’s still possible for Arctic tundra to flip in the other direction, so that it absorbs more carbon than it emits. The only way to do that is to reduce global greenhouse gas emissions.
said Brendan Rogers, a scientist at the Woodwell Climate Research Center who contributed to the Arctic Report Card. NPR“With lower levels of climate change, you get lower levels of emissions from permafrost… This should motivate us all to work toward more aggressive emissions reductions.”
However, this is unlikely to happen as the world continues to emit greenhouse gases into the atmosphere at unprecedented levels. New research by 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 estimated emissions from land-use change (such as deforestation) of 4.2 billion tons, total CO2 emissions are projected to be 41.6 billion tons in 2024, up from 40.6 billion tons last year,” the study said.
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