Wildfires' Hidden Climate Benefit: Suppression of Biogenic Methane Production

Research conducted by the Southern California Coastal Water Research Project has uncovered a previously unrecognized impact of wildfires on global climate change. According to the study, wildfire chars possess an electron storage capacity that can support char-respiring microbes, enabling them to outcompete methanogens and suppress biogenic methane production. This finding has significant implications for understanding the full climate impacts of wildfires and deforestation.

Key Takeaways:

• The study collected 18 chars from fires between March and October 2023, all of which possessed sizable electron storage capacity, ranging from 0.54 to 2.85 mmol e/g.
• The chars were found to support char-respiring microbes, which outcompeted methanogens, suppressing biogenic methane production.
• The study demonstrated that, on average, 28.4 ± 2.2% of the wildfire chars' electron storage capacity was utilized to divert electrons away from methane production.
• Aeration of microbially utilized chars restored their capacity to suppress methane production, confirming the redox-reversible nature of electron storage capacity.
• The research provides the first significant dataset of wildfire char electron storage capacity and demonstrates the quantitative suppression of biogenic methane production by wildfire chars.

Statistics:

• 18 chars were collected from fires between March and October 2023.
• Electron storage capacity of chars ranged from 0.54 to 2.85 mmol e/g.
• 28.4 ± 2.2% of the wildfire chars' electron storage capacity was utilized to divert electrons away from methane production.

Sources:

• NewsRx. New Science Data Have Been Reported by Researchers at Southern California Coastal Water Research Project (A New Climate Impact of Wildfire Chars: Suppression of Biogenic Methane Production Over Repeated Redox Cycles). Chemicals & Chemistry. August 15, 2025; p 1997.
• A New Climate Impact of Wildfire Chars: Suppression of Biogenic Methane Production Over Repeated Redox Cycles. Environmental Science & Technology, 2025.