Burning of forest materials under late Paleozoic high atmospheric oxygen levels

Abstract

Theoretical models suggest that atmospheric oxygen reached concentrations as high as 35% O₂ during the past 550 m.y. Previous burning experiments using strips of paper have challenged this idea, concluding that ancient wildfires would have decimated plant life if O₂ significantly exceeded its present level of 21%. New thermochemistry and flame-spread experiments using natural fuels contradict these results and indicate that sustained burning of forest fuels at moisture contents common to living plants does not occur between 21% and 35% O₂. Therefore, the fires under atmospheres with high oxygen concentrations would not have prevented the persistence of plant communities. Times of high O₂ also agree with observations of concurrent fire-resistant plant morphology, large insects, and high concentrations of fossil charcoal.

Citation

Wildman, Richard A., Jr.; Hickey, Leo J.; Dickinson, Matthew B.; Berner, Robert A.; Robinson, Jennifer M.; Dietrich, Michael; Essenhigh, Robert H.; Wildman, Craig B. 2004. Burning of forest materials under late Paleozoic high atmospheric oxygen levels. Geology 32(5):457-460