A study has been published indicating that even if carbon neutrality is achieved, permafrost will still be a source of carbon emissions in the atmosphere. The analysis suggests that the impacts of past carbon emissions will last as long as the year 2300.
Professor 국종성 of the Department of Earth and Environmental Sciences at Seoul National University and his research team announced these findings on the 13th through an international collaborative study involving Yonsei University, Norway, and the United States. The study has been published in the international journal "Science Advances."
Permafrost has historically balanced microbial respiration and plant carbon absorption, serving as a carbon sink. However, as global warming intensifies, permafrost has begun to thaw, revealing frozen plants that decompose or lead to increased microbial respiration, creating a vicious cycle of greenhouse gas emissions.
The lead author of the study, 박소원, a researcher in the Department of Environmental Engineering at Pohang University of Science and Technology, noted that "permafrost has acted as a tipping point for climate change" and explained that the research was conducted because it was uncertain what impact permafrost would have, even if carbon neutrality or carbon negativity was achieved.
To analyze how permafrost changes under carbon neutrality and carbon negativity scenarios, the research team utilized the Community Earth System Model 2 (CESM2) and Community Land Model 5 (CLM5). They simulated changes in permafrost extent and thickness, as well as the rates of carbon dioxide (CO₂) and methane (CH₄) emissions and absorptions from 2000 to 2300.
The study found that even if carbon neutrality or carbon negativity is achieved by 2050 as targeted by the Paris Agreement, the permafrost could not be prevented from transitioning from a carbon sink to a carbon source. This is due to the slow recovery rate of permafrost and continued microbial respiration, which maintained carbon emissions. The process of carbon moving from trees to soil, leading to delayed emissions, was also found to have an impact.
The research team estimates that by 2300, a total of 14 petagrams of carbon (PgC), or 14 trillion kg of carbon, will be additionally released into the atmosphere. They also indicated that there is a high likelihood that permafrost will continue to remain a carbon source even after 2300. Previous studies had predicted that achieving carbon neutrality and carbon negativity might lead to the recovery of permafrost.
박 박사 emphasized that "permafrost could pose significant risks to climate change mitigation efforts" and noted, "It is essential to consider changes in permafrost when establishing long-term climate policies."
References
Science Advances (2025), DOI: https://doi.org/10.1126/sciadv.adn8819